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1
Niswender, Gordon D., Jennifer L. Juengel, Patrick J. Silva, M. Keith Rollyson, and Eric W. McIntush. "Mechanisms Controlling the Function and Life Span of the Corpus Luteum." Physiological Reviews 80, no. 1 (January 1, 2000): 1–29. http://dx.doi.org/10.1152/physrev.2000.80.1.1.
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The primary function of the corpus luteum is secretion of the hormone progesterone, which is required for maintenance of normal pregnancy in mammals. The corpus luteum develops from residual follicular granulosal and thecal cells after ovulation. Luteinizing hormone (LH) from the anterior pituitary is important for normal development and function of the corpus luteum in most mammals, although growth hormone, prolactin, and estradiol also play a role in several species. The mature corpus luteum is composed of at least two steroidogenic cell types based on morphological and biochemical criteria and on the follicular source of origin. Small luteal cells appear to be of thecal cell origin and respond to LH with increased secretion of progesterone. LH directly stimulates the secretion of progesterone from small luteal cells via activation of the protein kinase A second messenger pathway. Large luteal cells are of granulosal cell origin and contain receptors for PGF2αand appear to mediate the luteolytic actions of this hormone. If pregnancy does not occur, the corpus luteum must regress to allow follicular growth and ovulation and the reproductive cycle begins again. Luteal regression is initiated by PGF2αof uterine origin in most subprimate species. The role played by PGF2αin primates remains controversial. In primates, if PGF2αplays a role in luteolysis, it appears to be of ovarian origin. The antisteroidogenic effects of PGF2αappear to be mediated by the protein kinase C second messenger pathway, whereas loss of luteal cells appears to follow an influx of calcium, activation of endonucleases, and an apoptotic form of cell death. If the female becomes pregnant, continued secretion of progesterone from the corpus luteum is required to provide an appropriate uterine environment for maintenance of pregnancy. The mechanisms whereby the pregnant uterus signals the corpus luteum that a conceptus is present varies from secretion of a chorionic gonadotropin (primates and equids), to secretion of an antiluteolytic factor (domestic ruminants), and to a neuroendocrine reflex arc that modifies the secretory patterns of hormones from the anterior pituitary (most rodents).
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Shukla, Akshara, Rohitash Jamwal, and Kumud Bala. "ADVERSE EFFECT OF COMBINED ORAL CONTRACEPTIVE PILLS." Asian Journal of Pharmaceutical and Clinical Research 10, no. 1 (January 1, 2016): 17. http://dx.doi.org/10.22159/ajpcr.2017.v10i1.14565.
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ABSTRACTOral contraceptive (OC) pills contain estrogen and progestin that are synthetic analogs of natural hormones. These synthetic hormones affectthe hypothalamus-pituitary-gonadal axis of the female reproductive system. There are many types of contraceptives; most of the OC pills preventpregnancy by inhibiting ovulation. Estrogen and progestin are two female reproductive hormones that are critical. Typically, estradiol is producedby growing follicle (ovaries) which stimulates the hypothalamus to produce the gonadotropin-releasing hormone, which further stimulates theanterior pituitary to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH). LH production triggers the ovulation. Similarly, theprogesterone is produced by corpus luteum (ovaries), which triggers the production of FSH and LH. There are many types of progesterone available.Long-term usage of synthetic estrogen and progesterone can disturb the balance between the level of these hormones in the body. This imbalance maylead to severe side effects such as breast cancer, cervical cancer, thrombosis, direct impact on the brain, and infertility.Keywords: Estrogen, Progesterone, Contraceptives, Herbal contraceptives.
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Thordarson, G., S. Galosy, G. O. Gudmundsson, B. Newcomer, R. Sridaran, and F. Talamantes. "Interaction of Mouse Placental Lactogens and Androgens in Regulating Progesterone Release in Cultured Mouse Luteal Cells." Endocrinology 138, no. 8 (August 1, 1997): 3236–41. http://dx.doi.org/10.1210/endo.138.8.5309.
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Abstract Pituitary hormones are essential for the maintenance of the corpus luteum in the pregnant mouse during the first half of gestation. Thereafter, hormones from the placenta take over the luteotropic role of the pituitary hormones. Mouse placental lactogen-I (mPL-I) and mPL-II, two PRL-like hormones produced in the placenta, are probably necessary for the maintenance of the corpus luteum in the latter half of pregnancy. A culture system of luteal cells from pregnant mice was developed to investigate the role of hormones from the placenta that may be important for the function of the corpus luteum. Mice were killed on days 10, 14, and 18 of pregnancy, and the corpora lutea were excised from the ovaries and digested in 0.1% collagenase, 0.002% DNase for 1 h. The resulting luteal cell suspension was plated onto 96-well plates coated with fibronectin (1 × 105 cells/well) and cultured for 1–3 days. Medium was changed daily. The cells were treated with various concentrations and combinations of mPL-I, mPL-II, mouse PRL, androstenedione, dihydrotestosterone, 17β-estradiol (E2), testosterone, hydroxyflutamide, cycloheximide, actinomycin D, and fadrozole to study the effects of these different treatments on progesterone (P4) production. The three lactogens (mPL-I, mPL-II, and mouse PRL) all stimulated the release of P4 from the luteal cells. The potency of the lactogens was similar and did not depend on the stage of pregnancy at which the luteal tissue was obtained. However, the responsiveness of the cells to all hormone-stimulated P4 release was gradually reduced the later in pregnancy the tissue was collected. Androgens also stimulated the release of P4 from the luteal cells, and when administered together, the lactogens and the androgens acted synergistically to stimulate P4 release. The androgens acted directly but not through conversion to E2, as determined by the findings that 1) the effects of the androgens could not be reproduced by E2 administration, 2) nonaromatizable androgen dihydrotestosterone was as effective as aromatizable androgens, and 3) aromatase inhibitor did not prevent the action of the androgens to stimulate the P4 release. The effect of the androgens on the P4 release was rapid, occurring within 15 min of hormone administration. It was not prevented by inhibitors of protein and RNA synthesis, and the intracellular androgen receptor antagonist hydroxyflutamide did not affect the androgen action. Therefore, the androgen effects were not mediated through the intracellular androgen receptor and de novo protein synthesis was not needed for androgen-stimulated P4 release.
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Tasende, C., M. Rodríguez-Piñón, S. Acuña, E. G. Garófalo, and M. Forsberg. "Corpus luteum life span and pituitary oestrogen and progesterone receptors in cyclic and gonadotrophin-releasing hormone-treated anoestrous ewes." Reproduction, Fertility and Development 17, no. 7 (2005): 721. http://dx.doi.org/10.1071/rd05058.
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The present study investigated the pituitary oestrogen (ER) and progesterone (PR) receptor concentrations in ewes during the oestrous cycle in the breeding season (n = 19), and in anoestrous ewes treated with gonadotrophin-releasing hormone (GnRH) (n = 11) and anoestrous ewes treated with progesterone + GnRH (n = 11). The pituitary ER and PR concentrations at the expected time of ovulation and in the early and late luteal phases were measured by binding assay. The pattern of pituitary ER and PR concentrations in the progesterone + GnRH-treated ewes resembled the pattern found during the normal oestrous cycle, with ER and PR concentrations decreasing from the time of ovulation to the early luteal phase. In contrast, in ewes treated with GnRH alone, ER and PR concentrations increased in the early luteal phase, which may increase the inhibitory effects of steroid hormones on luteinising hormone secretion, ultimately leading to the development of subnormal luteal phases.
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Nishimura, Ryo, and Kiyoshi Okuda. "Multiple roles of hypoxia in ovarian function: roles of hypoxia-inducible factor-related and -unrelated signals during the luteal phase." Reproduction, Fertility and Development 28, no. 10 (2016): 1479. http://dx.doi.org/10.1071/rd15010.
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There is increasing interest in the role of oxygen conditions in the microenvironment of organs because of the discovery of a hypoxia-specific transcription factor, namely hypoxia-inducible factor (HIF) 1. Ovarian function has several phases that change day by day, including ovulation, follicular growth and corpus luteum formation and regression. These phases are regulated by many factors, including pituitary hormones and local hormones, such as steroids, peptides and cytokines, as well as oxygen conditions. Hypoxia strongly induces angiogenesis because transcription of the potent angiogenic factor vascular endothelial growth factor (VEGF) is regulated by HIF1. Follicular development and luteal formation are accompanied by a marked increase in angiogenesis assisted by HIF1–VEGF signalling. Hypoxia is also one of the factors that induces luteolysis by suppressing progesterone synthesis and by promoting apoptosis of luteal cells. The present review focuses on recent studies of hypoxic conditions, as well as HIF1-regulated genes and proteins, in the regulation of ovarian function.
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Kovalishin, O. A. "Features of hormonal and cytokine status in women with menstrual dysfunction in the puberty." HEALTH OF WOMAN, no. 7(153) (September 29, 2020): 56–61. http://dx.doi.org/10.15574/hw.2020.153.56.
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Deviations in the formation of reproductive function, and subsequently menstrual irregularities from the age of menarche, ovarian dysfunction and steroidogenesis disorders can be clinically manifested in remote periods after their direct action. The nature and depth of morphofunctional disorders in this case depends on the degree of maturity of the reproductive system, the initial functional state of the regulation centers (hypothalamus, pituitary gland) and ovaries, and the duration of the action of adverse factors. The accumulated specific research experience indicates that in addition to the pituitary gonadotropin hormones, cytokines (interleukins), which can simulate ovarian function and play an important role in ovulation, are of great importance in the normal functioning of the ovaries. The objective: аccording to laboratory and instrumental methods of research, to study the characteristics of hormonal status and the relationship of ovarian hormones with interleukins (IL) in women with menstrual dysfunction in the puberty. Materials and methods. According to the nature of the violations, the main group of women (n=90) who had a pathology of menstrual function in the puberty period was divided into 3 subgroups (n=30): the first – women with primary oligomenorrhea in the anamnesis, the second – with a late age menarche, the third – with puberty bleeding. The control group included women (n=30) with the correct rhythm of menstruation in puberty. Results. A clinical study found a decrease in the concentration of progesterone in women with a history of primary oligomenorrhea, a decrease in estradiol in the preovulatory period in women with late menarche. When assessing the concentration of follicle-stimulating hormone in the subgroups, an increase was noted in patients with puberty bleeding compared with the control group, due to the low level of antimuller hormone in the blood serum. The correlation between the indicators of these hormones and interleukins (IL-4, IL-8) indicates the influence of cytokines on folliculogenesis and the formation of the corpus luteum. Ovarian reserve parameters are not reduced. Conclusion. An analysis of the hormonal and cytokine status in women with menstrual dysfunction in the puberty allows us to draw an analogy between the processes of ovulation and the inflammatory response. The cytokines produced by certain immune cells are signaling molecules that affect cell proliferation and apoptosis of ovarian cells, folliculogenesis, hormone secretion and thus play an important role in ovulation. Therefore, the immune system may be an additional local regulator of ovarian function. Estradiol and progesterone are of great importance in the secretory transformation of the endometrium, especially during the «implantation window». Keywords: puberty, menarche, oligomenorrhea, pubertal bleeding, folliculogenesis, progesterone, estradiol, interleukins, pituitary gland, anti-varial antibodies.
7
Hinds, LA, TP Fletcher, and JC Rodger. "Hormones of oestrus and ovulation and their manipulation in marsupials." Reproduction, Fertility and Development 8, no. 4 (1996): 661. http://dx.doi.org/10.1071/rd9960661.
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Oestrus and ovulation occur spontaneously in the majority of marsupials, with behavioural oestrus usually occurring 1-2 days before ovulation. The hormone changes that occur at this time have been described in the most detail for the monovular tammar wallaby Macropus eugenii. The respective roles of the Graafian follicle, corpus luteum and the pituitary in the events leading up to oestrus and ovulation in this species are also reviewed. Recently, various protocols have been developed for superovulation of marsupials, including Australian species, such as the brush-tailed possum, fat-tailed dunnart, brush-tailed bettong and tammar wallaby, and the American laboratory opossum, Monodelphis domestica. These protocols provide an opportunity for studying the regulation of ovarian activity and for the collection of larger quantities of material for the study of gamete maturation, in vitro fertilization and embryonic development.
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Gonzalez-Bulnes, Antonio, Alejo Menchaca, Graeme B. Martin, and Paula Martinez-Ros. "Seventy years of progestagen treatments for management of the sheep oestrous cycle: where we are and where we should go." Reproduction, Fertility and Development 32, no. 5 (2020): 441. http://dx.doi.org/10.1071/rd18477.
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Management of the ovine oestrous cycle is mainly based on the use of exogenous hormones to mimic or enhance (progesterone and its analogues) or manipulate (prostaglandin F2α and its analogues) the activity of the corpus luteum, combined with the application of other hormones mimicking the pituitary secretion of gonadotrophins (e.g. equine chorionic gonadotrophin). These protocols have been applied without major change for decades but, now, there are two reasons to reconsider them: (1) our greatly improved knowledge of the dynamics of ovarian physiology, following the application of transrectal ultrasonography, indicates that modification of the protocols may improve fertility yields and (2) increasing concerns about animal health and welfare, food safety and the environmental impact of the treatments, as evidenced by public opinion and therefore market forces. Here, we offer an overview of these issues, introduce an updated protocol and suggest ways for future improvements to the protocols.
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Fraser, H. M., M. Abbott, N. C. Laird, A. S. McNeilly, J. J. Nestor, and B. H. Vickery. "Effects of an LH-releasing hormone antagonist on the secretion of LH, FSH, prolactin and ovarian steroids at different stages of the luteal phase in the stumptailed macaque (Macaca arctoides)." Journal of Endocrinology 111, no. 1 (October 1986): 83–90. http://dx.doi.org/10.1677/joe.0.1110083.
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ABSTRACT The role of the pituitary gonadotrophins in controlling luteal function in the stumptailed macaque has been investigated by examining profiles of serum concentrations of LH, FSH, progesterone and oestradiol in daily blood samples from 13 monkeys during the menstrual cycle, and in blood samples taken at hourly intervals between 09.00 and 21.00 h on different days of the luteal phase in 13 cycles. The effects of acute withdrawal of gonadotrophins was investigated by administering a single injection of 300 μg LHRH antagonist/kg body weight at different stages of the luteal phase during 28 cycles. Although there were high basal values and marked fluctuations of bioactive LH during the first 4 days after the LH peak, progesterone profiles showed no corresponding short-term changes, there being a slow and steady rise in progesterone concentrations during the sampling periods. After day 5, basal LH secretion decreased, but high amplitude LH pulses were identified which were associated with episodes of progesterone secretion. Administration of the LHRH antagonist caused a suppression of bioactive LH and progesterone concentrations at all stages of the luteal phase, although some basal secretion of progesterone was maintained through the 24-h period of effective antagonist gonadotroph blockade. Luteal function recovered apparently normally in all monkeys treated in the early–mid-luteal phase. Serum concentrations of FSH and oestradiol fluctuated comparatively less during the 12-h sampling periods, and the antagonist had less suppressive effects on the concentrations of these hormones. The LHRH antagonist had no apparent effect on prolactin release. It appears that the corpus luteum is relatively unresponsive to the high serum LH concentrations during the early luteal phase, but that responsiveness increases as the corpus luteum develops. The corpus luteum is, however, susceptible to withdrawal of LH not only in the mid–late luteal phase when the relationship with LH is apparent, but also during the early luteal phase. J. Endocr. (1986) 111, 83–90
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Tandeski, TR, JL Juengel, TM Nett, and GD Niswender. "Regulation of mRNA encoding low density lipoprotein receptor and high density lipoprotein-binding protein in ovine corpora lutea." Reproduction, Fertility and Development 8, no. 7 (1996): 1107. http://dx.doi.org/10.1071/rd9961107.
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Three experiments were conducted to examine the regulation of steady-state concentrations of mRNA encoding ovine low density lipoprotein receptor (LDL-R) and high density lipoprotein-binding protein (HBP) in corpora lutea. In Experiment 1, corpora lutea were collected from ewes on Days 3, 6, 9, 12 and 15 (Day 0, oestrus) of the oestrous cycle. Enriched preparations of small and large steroidogenic luteal cells were also obtained on Days 6, 9, 12 and 15 of the oestrous cycle. In Experiment 2, 16 ewes were hypophysectomized on Day 5 of the oestrous cycle and received saline, luteinizing hormone (LH), growth hormone (GH) or a combination of LH+GH until collection of luteal tissue on Day 12 of the oestrous cycle. Corpora lutea were also collected from pituitary-intact control ewes on Day 5 and Day 12 of the oestrous cycle. In Experiment 3, 13 ewes on Day 11 or Day 12 of the oestrous cycle were administered prostaglandin F2 alpha (PGF2 alpha) and corpora lutea were collected 4 h, 12 h and 24 h later. Corpora lutea were also collected from 4 non-injected and 4 saline-injected (at 24 h) ewes. Results demonstrated that concentrations of mRNA encoding LDL-R did not differ throughout the oestrous cycle. Luteal tissue collected on Day 3 of the oestrous cycle had higher concentrations of mRNA encoding HBP than luteal tissue collected on any other day of the oestrous cycle. Hypophysectomy increased concentrations of mRNA encoding LDL-R but had no effect on concentrations of mRNA encoding HBP. Twelve hours following PGF2 alpha injection concentrations of mRNA encoding LDL-R were decreased but concentrations of mRNA encoding HBP were increased. Concentrations of both LDL-R and HBP mRNA were decreased 24 h following injection of PGF2 alpha. Thus, long-term positive and acute negative regulation of progesterone secretion from the corpus luteum by luteotrophic and luteolytic hormones was not mediated by changes in steady-state concentrations of mRNA encoding LDL-R or HBP.
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Conrad, Kirk P., Georgia M. Graham, Yueh-Yun Chi, Xiaoman Zhai, Minjie Li, R. Stan Williams, Alice Rhoton-Vlasak, Mark S. Segal, Charles E. Wood, and Maureen Keller-Wood. "Potential influence of the corpus luteum on circulating reproductive and volume regulatory hormones, angiogenic and immunoregulatory factors in pregnant women." American Journal of Physiology-Endocrinology and Metabolism 317, no. 4 (October 1, 2019): E677—E685. http://dx.doi.org/10.1152/ajpendo.00225.2019.
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Cardiovascular function is impaired and preeclampsia risk elevated in women conceiving by in vitro fertilization (IVF) in the absence of a corpus luteum (CL). Here, we report the serial evaluation of hormones and other circulating factors in women who conceived with (or without) IVF. After a prepregnancy baseline, the study participants ( n = 19–24/cohort) were evaluated six times during pregnancy and once postpartum (~1.6 yr). IVF pregnancies were stratified by protocol and CL number, i.e., ovarian stimulation (>1 CL) or hypothalamic-pituitary suppression (0 CL) versus spontaneous conceptions (1 CL). Results include the following: 1) relaxin was undetectable throughout pregnancy (including late gestation) in the 0 CL cohort, but markedly elevated in ~50% of women in the >1 CL cohort; 2) progesterone, plasma renin activity, and aldosterone transiently surged at 5–6 gestational weeks in the >1 CL group; 3) soluble vascular endothelial growth factor-1 (sFLT-1) abruptly increased between 5–6 and 7–9 gestational weeks in all three participant cohorts, producing a marked elevation in sFLT-1/PLGF (placental growth factor) ratio exceeding any other time point during pregnancy; 4) sFLT-1 was higher throughout most of gestation in both IVF cohorts with or without abnormal obstetrical outcomes; 5) during pregnancy, C-reactive protein (CRP) increased in 0 and 1 CL, but not >1 CL cohorts; and 6) plasma protein, but not hemoglobin, was lower in the >1 CL group throughout gestation. The findings highlight that, compared with spontaneously conceived pregnancy, the maternal milieu of IVF pregnancy is not physiologic, and the specific perturbations vary according to IVF protocol and CL status.
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Pinheiro, V. G., J. R. L. M. Cury, R. A. Satrapa, M. F. Pegorer, and C. M. Barros. "63 EVALUATION OF HYPOTHALAMIC–PITUITARY RESPONSIVENESS DURING THE POSTPARTUM NELLORE COWS." Reproduction, Fertility and Development 24, no. 1 (2012): 144. http://dx.doi.org/10.1071/rdv24n1ab63.
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The presence of calf, body condition score, energy balance, number of births (multiparous vs primiparous) and breed are factors that influence the duration of postpartum anoestrus in beef cows. The objective of the present study was to evaluate, during early postpartum, the time of re-establishment of pituitary LH stocks, measured by the hypothalamic-pituitary-axis responsiveness to exogenous administration of gonadotropin-releasing hormone (GnRH) or oestradiol benzoate (EB). Multiparous lactating Nellore cows (Bos indicus, n = 65) were randomly allocated into 6 groups, according to the hormonal treatment: EB group (1.0 mg of EB, IM, n = 7), GnRH group (50 μg of lecireline, IM, n = 16). The EB-supplemented (SUP; n = 9) and GnRH-SUP (n = 16) groups received the same treatments specified above and were SUP with a balanced diet, based on cotton meal and ground corn (3.5 kg cow–1 per day). Additionally, animals from EB-calf removed (CR; n = 4) and GnRH-CR (n = 13) groups received the same treatments of EB and GnRH group, respectively and had their CR shortly after parturition. The hormones were administered weekly, from 7 days postpartum (±5 days) until the occurrence of the first ovulation, which was determined by the presence of corpus luteum during ovarian ultrasonography performed weekly. Blood samples were collected just before and 2 h (GnRH groups) or 18 h (EB groups) after hormone administration, in order to determine LH concentration by radioimmunoassay. Data were analysed by ANOVA. Mean values in days (± standard error of the means) for the first postpartum LH surge were EB (73.0 ± 5.2); EB-CR (16.7 ± 5.8); EB-SUP (41.7 ± 6.7); GnRH (32.3 ± 3.0); GnRH-CR (11.0 ± 3.5); GnRH-SUP (15.6 ± 2.8). There were significant differences (P < 0.05) between groups EB vs EB-CR; EB vs EB-SUP; BE vs GnRH; GnRH vs GnRH-CR; GnRH vs GnRH-SUP and a tendency between EB-SUP vs EB-CR (P < 0.10). Results indicate that from the second week postpartum, there is sufficient LH in the pituitary to induce ovulation after GnRH or EB administration. However, the cows from the EB group ovulated later than animals from the other groups, possibly due to the sensitivity of the hypothalamus to negative feedback of estrogens, inhibiting the pre-ovulatory LH surge. Additionally, CR and food SUP reduced in 2 to 4 weeks the time of the first postpartum LH surge induced by GnRH or EB in Nellore cows. A fellowship was received from FAPESP. Support was received from FAPESP.
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Gadkari, R. A., S. Roy, N. Rekha, N. Srinivasan, and R. R. Dighe. "Identification of a heterodimer-specific epitope present in human chorionic gonadotrophin (hCG) using a monoclonal antibody that can distinguish between hCG and human LH." Journal of Molecular Endocrinology 34, no. 3 (June 2005): 879–87. http://dx.doi.org/10.1677/jme.1.01683.
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Human chorionic gonadotrophin (hCG) is secreted during early pregnancy and is required for implantation and maintenance of the pregnancy. Active or passive immunoneutralization of hCG results in termination of pregnancy and this forms the basis of the hCG-based female contraceptive vaccine. However, the β subunit of hCG possesses 85% sequence homology with the first 114 amino acids of the β subunit of pituitary human LH (hLH), which is required for ovulation and maintenance of the corpus luteum function during the menstrual cycle. Immunization against hCG or its β subunit leads to generation of antibodies that can neutralize hLH due to many shared epitopes and hence may cause abnormal menstrual cycles. Therefore, it is essential to identify epitopes that are different in the two hormones. In the present study, we report a monoclonal antibody (MAb) specific for hCG that shows no binding to the isolated subunits. Interestingly, the MAb also does not bind hLH at all. The epitope mapping analysis revealed that this antibody recognizes a unique discontinuous epitope present only in the heterodimeric hCG and is distinct from the unique C-terminal extension of hCGβ that is absent in hLHβ. The MAb, either as IgG or its recombinant single-chain variable region fragment, inhibited the response to hCG, but not to hLH. Thus, the epitope recognized by this MAb is an ideal candidate antigen for immunocontraception.
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Tahir, Muhammad S., Loan T. Nguyen, Benjamin L. Schulz, Gry A. Boe-Hansen, Milton G. Thomas, Stephen S. Moore, Li Yieng Lau, and Marina R. S. Fortes. "Proteomics Recapitulates Ovarian Proteins Relevant to Puberty and Fertility in Brahman Heifers (Bos indicus L.)." Genes 10, no. 11 (November 12, 2019): 923. http://dx.doi.org/10.3390/genes10110923.
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High fertility and early puberty in Bos indicus heifers are desirable and genetically correlated traits in beef production. The hypothalamus–pituitary–ovarian (HPO) axis synthesizes steroid hormones, which contribute to the shift from the pre-pubertal state into the post-pubertal state and influence subsequent fertility. Understanding variations in abundance of proteins that govern steroid synthesis and ovarian signaling pathways remains crucial to understanding puberty and fertility. We used whole ovaries of six pre-pubertal and six post-pubertal Brahman heifers to conduct differential abundance analyses of protein profiles between the two physiological states. Extracted proteins were digested into peptides followed by identification and quantification with massspectrometry (MS) by sequential window acquisition of all instances of theoretical fragment ion mass spectrometry (SWATH-MS). MS and statistical analysis identified 566 significantly differentially abundant (DA) proteins (adjusted p < 0.05), which were then analyzed for gene ontology and pathway enrichment. Our data indicated an up-regulation of steroidogenic proteins contributing to progesterone synthesis at luteal phase post-puberty. Proteins related to progesterone signaling, TGF-β, retinoic acid, extracellular matrix, cytoskeleton, and pleiotrophin signaling were DA in this study. The DA proteins probably relate to the formation and function of the corpus luteum, which is only present after ovulation, post-puberty. Some DA proteins might also be related to granulosa cells signaling, which regulates oocyte maturation or arrest in ovaries prior to ovulation. Ten DA proteins were coded by genes previously associated with reproductive traits according to the animal quantitative trait loci (QTL) database. In conclusion, the DA proteins and their pathways were related to ovarian activity in Bos indicus cattle. The genes that code for these proteins may explain some known QTLs and could be targeted in future genetic studies.
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Fraser, H. M., D. T. Baird, G. I. McRae, J. J. Nestor, and B. H. Vickery. "SUPPRESSION OF LUTEAL PROGESTERONE SECRETION IN THE STUMPTAILED MACAQUE BY AN ANTAGONIST ANALOGUE OF LUTEINIZING HORMONE RELEASING HORMONE." Journal of Endocrinology 104, no. 2 (February 1985): R1—R4. http://dx.doi.org/10.1677/joe.0.104r001.
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ABSTRACT The dependence of progesterone secretion from the corpus luteum on pituitary gonadotrophin was examined in the cyclic stumptailed macaque by studying the effects of a single s.c. injection of a potent LH releasing hormone (LHRH) antagonist, [N–Ac–D–Nal(2)1, D–pCl–phe2, D–Trp3, D–hArg(Et2)6, D–Ala10] LHRH. A dose of 100 μg antagonist/kg administered on days 9/10 of the luteal phase in three monkeys caused a marked temporary suppression of serum concentrations of LH and progesterone during the following 32 h but levels still remained detectable and after 2 days serum hormone concentrations returned to the normal luteal-phase range. When the same animals were treated with 300 μg antagonist/kg at the same period during a subsequent cycle, serum LH levels were close to or at the limits of detection of the bioassay for the next 48 h and progesterone concentrations declined steadily, reaching non-detectable values by 48 h. In two monkeys the progesterone levels remained suppressed and they menstruated prematurely; in the third monkey the progesterone concentration rose to just above baseline and menstruation occurred at the expected time. Administration of 300μg antagonist/ kg on days 6/7 of the luteal phase in a further three monkeys also suppressed progesterone concentrations but not to baseline values, and after 2 days a normal progesterone profile was regained. These results suggest that the corpus luteum of the stumptailed macaque is largely dependent on pituitary gonadotrophin support during the mid to late luteal phase.
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Inayama, Yoshihide, Koji Yamanoi, Baku Nakakita, Shimpei Shitanaka, Jumpei Ogura, Tsutomu Ohara, Mie Sakai, et al. "A Case of Recurrent Hemorrhagic Corpus Luteum with Elevated Follicle-Stimulating Hormone, Controlled by Estrogen/Gestagen Therapy." Case Reports in Obstetrics and Gynecology 2020 (July 26, 2020): 1–6. http://dx.doi.org/10.1155/2020/4098085.
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A high secretion of follicle-stimulating hormone (FSH) in reproductive-aged women is unusual. We report a case of recurrent corpus luteum hemorrhage and subsequent ovarian torsion with markedly elevated FSH levels in a reproductive-aged woman in the absence of functional gonadotroph adenoma (FGA) or premature ovarian failure (POF). A 22-year-old nulligravid woman with a history of bilateral hemorrhagic corpus luteum and subsequent ovarian torsion presented with acute abdominal pain. An emergency salpingo-oophorectomy of the right side was performed, and the right ovarian torsion due to hemorrhagic corpus luteum was diagnosed. Laboratory tests revealed markedly elevated FSH levels (77.6 mIU/mL). FGA was suspected, but no evidence of tumor was identified. The left ovary enlarged again at one-month follow-up. Estrogen/gestagen therapy (EGT) was started, which reduced the enlarged ovary to normal size. Two years later, her pituitary hormonal status was evaluated in detail. Besides markedly elevated FSH level, slightly elevated LH (31.2 mIU/mL), normal total inhibin B (35.3 pg/ml), abnormally low anti-Müllerian hormone (AMH) (<0.03 ng/mL), and poor FSH response to gonadotropin-releasing hormone stimulation test were found. In the absence of FGA, we conclude that certain disorders of inhibitory factors for FSH function, including inhibin and AMH may exist, which could attribute to the patient’s symptoms. EGT was very effective in suppressing the ovarian hyperactivity.
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Gimpl, Gerald, and Falk Fahrenholz. "The Oxytocin Receptor System: Structure, Function, and Regulation." Physiological Reviews 81, no. 2 (April 1, 2001): 629–83. http://dx.doi.org/10.1152/physrev.2001.81.2.629.
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The neurohypophysial peptide oxytocin (OT) and OT-like hormones facilitate reproduction in all vertebrates at several levels. The major site of OT gene expression is the magnocellular neurons of the hypothalamic paraventricular and supraoptic nuclei. In response to a variety of stimuli such as suckling, parturition, or certain kinds of stress, the processed OT peptide is released from the posterior pituitary into the systemic circulation. Such stimuli also lead to an intranuclear release of OT. Moreover, oxytocinergic neurons display widespread projections throughout the central nervous system. However, OT is also synthesized in peripheral tissues, e.g., uterus, placenta, amnion, corpus luteum, testis, and heart. The OT receptor is a typical class I G protein-coupled receptor that is primarily coupled via Gq proteins to phospholipase C-β. The high-affinity receptor state requires both Mg2+ and cholesterol, which probably function as allosteric modulators. The agonist-binding region of the receptor has been characterized by mutagenesis and molecular modeling and is different from the antagonist binding site. The function and physiological regulation of the OT system is strongly steroid dependent. However, this is, unexpectedly, only partially reflected by the promoter sequences in the OT receptor gene. The classical actions of OT are stimulation of uterine smooth muscle contraction during labor and milk ejection during lactation. While the essential role of OT for the milk let-down reflex has been confirmed in OT-deficient mice, OT's role in parturition is obviously more complex. Before the onset of labor, uterine sensitivity to OT markedly increases concomitant with a strong upregulation of OT receptors in the myometrium and, to a lesser extent, in the decidua where OT stimulates the release of PGF2α. Experiments with transgenic mice suggest that OT acts as a luteotrophic hormone opposing the luteolytic action of PGF2α. Thus, to initiate labor, it might be essential to generate sufficient PGF2α to overcome the luteotrophic action of OT in late gestation. OT also plays an important role in many other reproduction-related functions, such as control of the estrous cycle length, follicle luteinization in the ovary, and ovarian steroidogenesis. In the male, OT is a potent stimulator of spontaneous erections in rats and is involved in ejaculation. OT receptors have also been identified in other tissues, including the kidney, heart, thymus, pancreas, and adipocytes. For example, in the rat, OT is a cardiovascular hormone acting in concert with atrial natriuretic peptide to induce natriuresis and kaliuresis. The central actions of OT range from the modulation of the neuroendocrine reflexes to the establishment of complex social and bonding behaviors related to the reproduction and care of the offspring. OT exerts potent antistress effects that may facilitate pair bonds. Overall, the regulation by gonadal and adrenal steroids is one of the most remarkable features of the OT system and is, unfortunately, the least understood. One has to conclude that the physiological regulation of the OT system will remain puzzling as long as the molecular mechanisms of genomic and nongenomic actions of steroids have not been clarified.
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Bramley, T. A., G. S. Menzies, and D. T. Baird. "Specificity of gonadotrophin-releasing hormone binding sites of the human corpus luteum: comparison with receptors of rat pituitary gland." Journal of Endocrinology 108, no. 3 (March 1986): 323–28. http://dx.doi.org/10.1677/joe.0.1080323.
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ABSTRACT The effects of a number of analogues of gonadotrophin-releasing hormone (GnRH) on the binding of a radiolabelled GnRH agonist (GnRH-A; d-Ser(But)6, des Gly10]GnRH-ethylamide) to homogenates of human corpus luteum (CL) and rat pituitary tissue were compared. Specific binding was inhibited by GnRH and GnRH-like peptides only. Both the C-terminal amide and N-terminal region of the GnRH molecule were required for binding in both tissues. However, amino acid substitutions at position 6 markedly enhanced, and at position 8 markedly reduced, binding potencies in rat pituitary tissue compared with human CL binding sites. These results indicate that GnRH-binding sites of rat pituitary and human luteal tissue have a similar degree of specificity for GnRH-like peptides, and a similar requirement for both N- and C-terminal regions of the peptide, but that differences in specificity related to the mid-chain region of GnRH exist between human luteal and rat pituitary binding sites. J. Endocr. (1985) 000, 000–000
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Auletta, F. J., D. S. C. Jones, and A. P. F. Flint. "Does the human corpus luteum synthesize neurohypophysial hormones?" Journal of Endocrinology 116, no. 2 (February 1988): 163–65. http://dx.doi.org/10.1677/joe.0.1160163.
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Macklon, NS, and BCJM Fauser. "Alternative approaches to ovarian stimulation for IVF." Reproductive Medicine Review 9, no. 1 (March 2001): 77–89. http://dx.doi.org/10.1017/s096227990100014x.
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Ovarian stimulation protocols applied world-wide today may take several weeks per stimulated cycle, are complex, expensive and associated with a certain degree of risk. Gonadotrophin preparations are administered to stimulate multiple follicle development usually at daily doses of 150–300 IU (and sometimes higher) for one to three weeks. A premature rise in serum luteinizing hormone (LH) levels, generally believed to be detrimental for in vitro fertilization (IVF) outcome, is prevented by the co-administration of a gonadotrophin-releasing hormone (GnRH) agonist. This is usually initiated in the preceding cycle to allow for pituitary downregulation to occur before the initiation of exogenous follicle-stimulating hormone (FSH). Finally, the resumption of oocyte meiotic maturation is induced by a single bolus injection of human chorionic gonadotrophin (hCG) during the late follicular phase. In addition, the corpus luteum is supported during the luteal phase by repeated administration of hCG or supplemented by exogenous progesterone.
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Sugatani, J., Y. Masu, M. Nishizawa, K. Sakamoto, T. Houtani, T. Sugimoto, and S. Ito. "Hormonal regulation of prostaglandin F2 alpha receptor gene expression in mouse ovary." American Journal of Physiology-Endocrinology and Metabolism 271, no. 4 (October 1, 1996): E686—E693. http://dx.doi.org/10.1152/ajpendo.1996.271.4.e686.
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In this study we examined regulation by pituitary gonadotropins of the prostaglandin F2 alpha (PGF2 alpha) receptor gene expression in the mouse ovary. Administration of pregnant mare serum gonadotropin (PMSG) to 35-day-old mice in the diestrus phase stimulated the ovary and enhanced the production of progesterone at 1 h PMSG also increased the ovarian PGF2 alpha receptor mRNA level in a time-dependent manner, reaching a sixfold maximum at 1 h. These actions of PMSG were mimicked by human chorionic gonadotropin (hCG), follicle-stimulating hormone (FSH), and cholera toxin, all of which elevate intracellular adenosine 3',5'-cyclic monophosphate (cAMP). In situ hybridization revealed that PGF2 alpha receptor mRNA was localized to the corpus luteum, but the intensity of staining varied among corpora lutea in the same ovary. Exogenous PGF2 alpha inhibited the PMSG-stimulated progesterone production. These results demonstrate that gonadotropins may induce the expression of the PGF2 alpha receptor gene in luteal cells of the corpus luteum, probably by acting through a cAMP-mediated pathway, and that expression of the PGF2 alpha receptor may be functionally associated with the decrease in serum progesterone level.
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Santoro, N., J. P. Butler, M. Filicori, and W. F. Crowley. "Alterations of the hypothalamic GnRH interpulse interval sequence over the normal menstrual cycle." American Journal of Physiology-Endocrinology and Metabolism 255, no. 5 (November 1, 1988): E696—E701. http://dx.doi.org/10.1152/ajpendo.1988.255.5.e696.
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Luteinizing hormone (LH) is released in a pulsatile fashion from the anterior pituitary in response to hypothalamic gonadotropin-releasing hormone (GnRH) secretion. Previous autocorrelation analysis of the sequence of interpulse intervals of LH secretion in normal men has supported the hypothesis that the underlying hypothalamic mechanism of GnRH secretion governing episodic LH release is a renewal process, indicating that hypothalamic "memory," if present, does not extend back further in time than the preceding secretory pulse. A similar analysis of pulsatile LH secretion was undertaken in 45 studies of normal women, obtained throughout the menstrual cycle. Analysis of these studies revealed a process consistent with renewal throughout the follicular and early luteal phases. However, this relationship appears to break down in the mid-to-late luteal phase, indicating that alternative feedback pathways provide an overriding influence on the underlying renewal process of hypothalamic GnRH secretion. Pulsatile progesterone secretion by the corpus luteum, which first emerges at this stage of the menstrual cycle, may be the agent responsible for this feedback.
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Journal, Baghdad Science. "The effect of aqueous crude extract of ginger on the histology of corpus luteum and the concentration of hormones estrogen and progesterone in pregnant mice." Baghdad Science Journal 12, no. 4 (December 6, 2015): 638–44. http://dx.doi.org/10.21123/bsj.12.4.638-644.
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This study was designed to investigate the effect of aqueous extract of ginger Zingiber officinale Roscoe on the histology of corpus luteum and the concentration of the hormones progesterone and estrogen during the first trimester of pregnancy (0 - 7) days from fertilization. 30 pregnant mice were divided into five experimental groups: control group (administrated with distilled water), and four groups treated at doses (284, 568, 1136,1420 mg / kg), orally administrated , daily with (0.1 ml). Microscopic examination results have shown histopathological changes in corpus luteum included: Pyknosis in some nuclei of granulosa cells, Karyorrhexis, Karyolysis in some granulosa cells, and necrosis in corpus luteum, with additional significant decrease in the average of diameters of corpus luteum at level (P
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Gemmell, RT. "A comparative study of the corpus luteum." Reproduction, Fertility and Development 7, no. 3 (1995): 303. http://dx.doi.org/10.1071/rd9950303.
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The corpus luteum (CL) is a transitory organ which has a regulatory role in reproduction. Sharks, amphibians and reptiles have corpora lutea that produce progesterone which influences the rate of embryonic development. The egg-laying monotremes and the two major mammalian groups, eutherian and marsupial, have a CL that secretes progesterone. Most eutherians have allowed for the uterine development of their young by extending the length of the oestrous cycle and the CL or placenta actively secretes progesterone until birth. Gestation in the marsupial does not extend beyond the length of an oestrous cycle and the major part of fetal development takes place in the pouch. Where the extension of the post-luteal phase in the eutherian has allowed for the uterine development of young, the marsupial has extended the pre-luteal phase of the oestrous cycle and has evolved an alternative reproductive strategy, embryonic diapause. The mechanism for the secretion of hormones from the CL has been controversial for many years. Densely-staining secretory granules have been observed in the CL of sharks, marsupials and eutherians. These granules have been reported to contain relaxin, oxytocin or mesotocin, and progesterone. A hypothesis to suit all available data is that all hormones secreted by the CL are transported within such granules. In conclusion, although there are obvious differences in the mode of reproduction in the two main mammalian groups, it is apparent that there is a great deal of similarity in the hormonal control of regression of the CL and parturition.
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Billhaq, Dody Houston, and Seunghyung Lee. "The Role of the Guanosine Nucleotide-Binding Protein in the Corpus Luteum." Animals 11, no. 6 (May 24, 2021): 1524. http://dx.doi.org/10.3390/ani11061524.
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The corpus luteum is a temporary endocrine gland in the ovary. In the ovarian cycle, repeated patterns of specific cellular proliferation, differentiation, and transformation occur that accompany the formation and regression of the corpus luteum. Molecular mechanism events in the ovarian microenvironment, such as angiogenesis and apoptosis, are complex. Recently, we focused on the role of RAS protein in the ovarian corpus luteum. RAS protein plays a vital role in the modulation of cell survival, proliferation, and differentiation by molecular pathway signaling. Additionally, reproductive hormones regulate RAS activity in the cellular physiological function of ovarian follicles during pre-ovulatory maturation and ovulation. Thus, we have reviewed the role of RAS protein related to the biological events of the corpus luteum in the ovary.
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Usuki, Satoshi, and Eri Kotani. "Tokishakuyakusan Directly Attenuates PACAP's Luteolytic Action on Luteal Function in the Rat Ovary." American Journal of Chinese Medicine 30, no. 04 (January 2002): 521–31. http://dx.doi.org/10.1142/s0192415x02000545.
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We investigated the potential direct effects of Tokishakuyakusan (TS) on progestin [progesterone and 20 α-hydroxyprogesterone (20 α-OH-P)] and cyclic adenosine-3', 5'-monophosphate (cAMP) production in cultured rat luteal cells. In addition, we examined whether TS regulates the inhibitory effects of pituitary adenylate cyclase-activating polypeptide (PACAP), a newly found peptide, on luteinizing hormone (LH)-stimulated progesterone production. TS significantly stimulated progesterone, but not 20α-OH-P, production and cAMP accumulation through 24 hours of culture. PACAP-38 significantly elevated progesterone, 20α-OH-P and cAMP levels at all concentrations studied. On the other hand, PACAP-38 inhibited the production of progesterone and the accumulation of cAMP enhanced by LH, while the ratio of progesterone to 20α-OH-P was significantly decreased by PACAP-38 + LH. Concomitant treatment with TS and PACAP-38 + LH increased the ratio of progesterone to 20α-OH-P more than with PACAP-38 + LH. The present data have demonstrated that TS stimulates progesterone production in rat luteal cells, reconfirming our previous evidence that TS stimulates luteal steroidogenesis. The data further suggest that TS tends to attenuate PACAP's inhibition of LH-stimulated progesterone production, suggesting a luteotrophic effect within the corpus luteum.
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Sun, Weiwei, Hui Xie, Ji Ji, Xiaojie Zhou, David Goltzman, and Dengshun Miao. "Defective female reproductive function in 1,25(OH)2D-deficient mice results from indirect effect mediated by extracellular calcium and/or phosphorus." American Journal of Physiology-Endocrinology and Metabolism 299, no. 6 (December 2010): E928—E935. http://dx.doi.org/10.1152/ajpendo.00378.2010.
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We used mice with targeted deletion of 25-hydroxyvitamin D 1α-hydroxylase [1α(OH)ase−/−] to investigate the effects of calcium and phosphorus on defects in the reproductive system of 1,25-dihydroxyvitamin D [1,25(OH)2D]-deficient female mice. The 1α(OH)ase−/− mice and their wild-type littermates were fed either a normal diet or a rescue diet (high calcium, phosphate, and lactose) starting from weaning until 3 mo of age. We then determined serum calcium and phosphorus levels, assessed gonadotropin and gonadal hormone production, and evaluated folliculogenesis, corpus luteum formation, ovarian angiogenesis, uterus development, and fertility. Results showed that hypocalcemic and hypophosphatemic female 1α(OH)ase−/− mice developed infertility accompanied by decreased estrogen and progestogen levels, elevated follicle-stimulating hormone and luteinizing hormone levels, defects in follicular development and corpus luteum formation, uterine hypoplasia, and decreased ovarian expression of angiogenic factors including vascular endothelial growth factor (VEGF), angiopoietin-1 and -2, and Tie-2. When serum calcium and phosphorus were normalized by the rescue diet, the defective reproductive phenotype in the female 1α(OH)ase−/− mice, including the dysfunction in the hypothalamic-pituitary-ovarian axis, and ovarian angiogenesis were reversed. These results indicate that the infertility seen in 1,25(OH)2D-deficient mice is not a direct effect of active vitamin D deficiency on the reproductive system but is an indirect effect mediated by extracellular calcium and phosphorus.
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Azuma, C., F. Saji, T. Kimura, Y. Tokugawa, M. Takemura, Y. Samejima, and O. Tanizawa. "Steroid hormones induce macrophage colony-stimulating factor (MCSF) and MCSF receptor mRNAs in the human endometrium." Journal of Molecular Endocrinology 5, no. 2 (October 1990): 103–8. http://dx.doi.org/10.1677/jme.0.0050103.
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ABSTRACT We investigated the biological effects of sex-steroid hormones, secreted from the corpus luteum and placenta, on the induction of mRNAs encoding macrophage colony-stimulating factor (MCSF) and c-fms proto-oncogene (MCSF receptor) in human endometrium. RNA was extracted from the placenta and endometrium of both pregnant and non-pregnant women, and Northern blot analysis was performed on poly(A)+ RNA using MCSF or c-fms proto-oncogene cDNA as the probe. Results showed: (1) that MCSF mRNA was expressed in the placenta and endometrium of the pregnant uterus, (2) that c-fms proto-oncogene mRNA was also expressed in the placenta and endometrium of the pregnant uterus, and (3) that exogenous sex-steroid hormones could induce the expression of MCSF and c-fms proto-oncogene mRNAs in the endometrium of non-pregnant women. These results indicate that sex-steroid hormones secreted by the corpus luteum and/or placenta influence endometrial and placental growth and differentiation via a mechanism of action involving local production of MCSF and its receptor.
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Papa, PC, and B. Hoffmann. "The Corpus Luteum of the Dog: Source and Target of Steroid Hormones?" Reproduction in Domestic Animals 46, no. 4 (February 21, 2011): 750–56. http://dx.doi.org/10.1111/j.1439-0531.2010.01749.x.
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Uilenbroek, J. Th J., P. J. A. Woutersen, and P. D. M. van der Vaart. "Steroid concentrations in rat corpora lutea isolated during the oestrous cycle and pseudopregnancy: effect of induction of ovulation at dioestrus." Journal of Endocrinology 120, no. 2 (February 1989): 325–30. http://dx.doi.org/10.1677/joe.0.1200325.
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ABSTRACT Corpora lutea could be identified under the dissection microscope up to 7 days after formation. They were isolated during the oestrous cycle and pseudopregnancy and the progesterone and 20α-OH-progesterone contents were compared with serum values of these steroids. The pattern of progesterone in serum resembled that found in the corpora lutea. However, the pattern of 20α-OH-progesterone concentrations in serum and corpora lutea were different. While 20α-OH-progesterone concentrations in the corpora lutea showed large variations during the cycle, changes in serum concentrations of 20α-OH-progesterone were relatively small. Measurement of hormone concentrations in isolated corpora lutea is therefore a sensitive method for studying corpus luteum activity. To study whether corpora lutea derived after ovulation of immature follicles showed deficient luteal activity, rats at dioestrus (2 days before pro-oestrus) were induced to ovulate by the injection of 10 IU human chorionic gonadotrophin (hCG) and subsequent luteal activity was studied by measuring hormone concentrations in the corpora lutea on day 5 of pseudopregnancy. Concentrations of progesterone, but not of 20α-OH-progesterone, in corpora lutea derived from follicles induced to ovulate at dioestrusday 1 were significantly lower than those in corpora lutea derived from follicles induced to ovulate at prooestrus. This difference was observed not only when pseudopregnancy was induced by cervical stimulation but also when it was induced by implantation of a pituitary gland under the kidney capsule. However, in the latter case, corpora lutea already present on the day of hCG injection also became activated. The present experiments demonstrate that by measuring hormone concentrations in isolated corpora lutea changes in luteal activity can be studied effectively. Moreover, it appears that corpora lutea derived from immature follicles contained less progesterone than those derived from fully mature follicles. Journal of Endocrinology (1989) 120, 325–330
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Duncan, W. Colin. "The inadequate corpus luteum." Reproduction and Fertility 2, no. 1 (February 26, 2021): C1—C7. http://dx.doi.org/10.1530/raf-20-0044.
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The corpus luteum is the source of progesterone in the luteal phase of the cycle and the initial two-thirds of the first trimester of pregnancy. Normal luteal function is required for fertility and the maintenance of pregnancy. Progesterone administration is increasingly used during fertility treatments and in early pregnancy to mitigate potentially inadequate corpus luteum function. This commentary considers the concept of the inadequate corpus luteum and the role and effects of exogenous progesterone. Progesterone supplementation does have important beneficial effects but we should be wary of therapeutic administration beyond or outside the evidence base. Lay summary After an egg is released a structure is formed on the ovary called a corpus luteum (CL). This produces a huge amount of a hormone called progesterone. Progesterone makes the womb ready for pregnancy but if a pregnancy does not happen the CL disappears after 12–14 days and this causes a period. If a pregnancy occurs, then the pregnancy hormone (hCG) keeps the CL alive and its progesterone supports the pregnancy for the next 6–8 weeks until the placenta takes over and the corpus luteum disappears. That means that if the CL is not working correctly there could be problems getting pregnant or staying pregnant. If a CL is not producing enough progesterone it usually means there is a problem with the growing or releasing of the egg and treatment should focus on these areas. In IVF cycles, where normal hormones are switched off, the CL does not produce quite enough progesterone before the pregnancy test and extra progesterone is needed at this time. In recurrent or threatened miscarriage, however, there is not any evidence that the CL is not working well or progesterone is low. However, there is benefit in taking extra progesterone if there is bleeding in early pregnancy in women with previous miscarriages. This might be because of the effects of high-dose progesterone on the womb or immune system. As changes to the hormone environment in pregnancy may have some life-long consequences for the offspring we have to be careful only to give extra progesterone when we are sure it is needed.
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WEBLEY, G. E., J. P. HEARN, and M. R. LUCK. "Local progesterone secretion by the marmoset corpus luteum after perfusion with regulating hormones." Acta Endocrinologica 116, no. 3_Suppl (August 1987): S111—S112. http://dx.doi.org/10.1530/acta.0.114s111a.
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Wojtysiak, Dorota, Ewa Kapkowska, Piotr Pasciak, and Branislav Zivkovic. "Steroid hormones concentration in the postovulatory follicles of the goose." Biotehnologija u stocarstvu 21, no. 1-2 (2005): 91–97. http://dx.doi.org/10.2298/bah0502091w.
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The purpose of the present investigation was to measure the concentrations of progesterone (P4), androgens (A) and estradiol (E2) in follicular wall of the three largest postovulatory follicles. The major findings in the present study are: 1) the postovulatory follicles of the goose, which are not homologous with the mammalian corpus luteum, are an active endocrine tissue. 2) Follicular wall of postovulatory follicles can synthesize large amounts of progesterone and lesser amounts of androgens and estradiol. This study also suggest that the steroidogenic potential of the follicular cells was markedly reduced during the process of follicular regression.
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Stocco, Carlos, Carlos Telleria, and Geula Gibori. "The Molecular Control of Corpus Luteum Formation, Function, and Regression." Endocrine Reviews 28, no. 1 (February 1, 2007): 117–49. http://dx.doi.org/10.1210/er.2006-0022.
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The corpus luteum (CL) is one of the few endocrine glands that forms from the remains of another organ and whose function and survival are limited in scope and time. The CL is the site of rapid remodeling, growth, differentiation, and death of cells originating from granulosa, theca, capillaries, and fibroblasts. The apparent raison d’etre of the CL is the production of progesterone, and all the structural and functional features of this gland are geared toward this end. Because of its unique importance for successful pregnancies, the mammals have evolved a complex series of checks and balances that maintains progesterone at appropriate levels throughout gestation. The formation, maintenance, regression, and steroidogenesis of the CL are among the most significant and closely regulated events in mammalian reproduction. During pregnancy, the fate of the CL depends on the interplay of ovarian, pituitary, and placental regulators. At the end of its life span, the CL undergoes a process of regression leading to its disappearance from the ovary and allowing the initiation of a new cycle. The generation of transgenic, knockout and knockin mice and the development of innovative technologies have revealed a novel role of several molecules in the reprogramming of granulosa cells into luteal cells and in the hormonal and molecular control of the function and demise of the CL. The current review highlights our knowledge on these key molecular events in rodents.
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Romero, Jared J., Alfredo Q. Antoniazzi, Natalia P. Smirnova, Brett T. Webb, Fang Yu, John S. Davis, and Thomas R. Hansen. "Pregnancy-associated genes contribute to antiluteolytic mechanisms in ovine corpus luteum." Physiological Genomics 45, no. 22 (November 15, 2013): 1095–108. http://dx.doi.org/10.1152/physiolgenomics.00082.2013.
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The hypothesis that ovine luteal gene expression differs due to pregnancy status and day of estrous cycle was tested. RNA was isolated from corpora lutea (CL) on days 12 and 14 of the estrous cycle (NP) or pregnancy (P) and analyzed with the Affymetrix bovine microarray. RNA also was isolated from luteal cells on day 10 of estrous cycle that were cultured for 24 h with luteolytic hormones (OXT and PGF) and secretory products of the conceptus (IFNT and PGE2). Differential gene expression (>1.5-fold, P < 0.05) was confirmed using semiquantitative real-time PCR. Serum progesterone concentrations decreased from day 12 to day 15 in NP ewes ( P < 0.05) reflecting luteolysis and remained >1.7 ng/ml in P ewes reflecting rescue of the CL. Early luteolysis ( days 12–14) was associated with differential expression of 683 genes in the CL, including upregulation of SERPINE1 and THBS1. Pregnancy on day 12 (55 genes) and 14 (734 genes) also was associated with differential expression of genes in the CL, many of which were ISGs (i.e., ISG15, MX1) that were induced when culturing luteal cells with IFNT, but not PGE2. Finally, many genes, such as PTX3, IL6, VEGF, and LHR, were stabilized during pregnancy and downregulated during the estrous cycle and in response to culture of luteal cells with luteolytic hormones. In conclusion, pregnancy circumvents luteolytic pathways and activates or stabilizes genes associated with interferon, chemokine, cell adhesion, cytoskeletal, and angiogenic pathways in the CL.
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Bramley, T. A., and G. S. Menzies. "Receptors for lactogenic hormones in the porcine corpus luteum: properties and luteal phase concentrations." Journal of Endocrinology 113, no. 3 (June 1987): 355–64. http://dx.doi.org/10.1677/joe.0.1130355.
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ABSTRACT Homogenates of pig corpora lutea contained specific, high-affinity receptors for ovine prolactin (oPRL) and human GH (hGH). Specific hormone binding was enhanced by divalent metal ions, but only when included in the binding reaction. Divalent metal ions did not act by increasing the recovery of bound hormone by low-speed centrifugation, but appeared to promote the formation of a more stable hormone– receptor complex. Both oPRL and hGH tracers were bound in similar amounts and with similar affinities by pig luteal homogenates and the concentrations of either unlabelled hormone required to displace specific binding of either tracer by 50% were identical. In contrast, 125I-labelled oGH failed to bind to pig luteal homogenates and oGH competed poorly for hGH or oPRL binding. Only hormones with prolactin-like activity competed for 125I-labelled oPRL binding. Specific prolactin binding was low in recently ovulated and early luteal phase corpora lutea, increased significantly in the mid-luteal phase and declined once more in the late luteal phase. Receptor concentrations increased with increasing gestational age. J. Endocr. (1987) 113, 355–364
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Przygrodzka, E., M. M. Kaczmarek, P. Kaczynski, and A. J. Ziecik. "Steroid hormones, prostanoids, and angiogenic systems during rescue of the corpus luteum in pigs." REPRODUCTION 151, no. 2 (February 2016): 135–47. http://dx.doi.org/10.1530/rep-15-0332.
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In order to characterize the transition of the corpora lutea (CL) from acquisition of luteolytic sensitivity to rescue of luteal function: i) the expression of 38 factors associated with steroids, prostanoids, and angiogenic systems and ii) concentrations of the main hormones responsible for maintenance of CL function in cyclic and pregnant pigs were examined. Additionally, the effect of prostaglandin (PG) E2 and F2α on luteal function during the estrous cycle and pregnancy was evaluated in vitro. Significantly up-regulated gene expression was revealed in CL collected on day 14 of the estrous cycle (CYP19A1, ESR2, PTGS2, HIF1A, and EDN1) and on days 12–14 of pregnancy (SCARB1, PGRMC1, STAR, HSD3B1, NR5A1, PTGFR, PTGER4, and VEGFA). Elevated concentrations of estradiol-17β and PGE2 occurred in CL on days 12 and 14 of pregnancy respectively, while an increased intraluteal PGF2α content was noted on day 14 of the estrous cycle. Both PGs increased the synthesis of progesterone by cultured luteal slices obtained on day 14 of pregnancy, in contrast to the action of PGF2α on the corresponding day of the estrous cycle. PGE2 stimulated cAMP production via PTGER2 and PTGER4, while PGF2α elevated the content of CREB in cultured luteal slices from CL of pregnant pigs. In silico analysis showed that infiltration of lymphocytes and apoptosis of microvascular endothelium were activated in CL on day 12 of the estrous cycle vs pregnancy. Summarizing, an abundance of E2 and PGE2 during pregnancy regulates specific pathways responsible for steroidogenesis, the prostanoid signaling system and angiogenesis during rescue from luteolysis in porcine CL.
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Hearn, J. P., and G. E. Webley. "Regulation of the corpus luteum of early pregnancy in the marmoset monkey: local interactions of luteotrophic and luteolytic hormones in vivo and their effects on the secretion of progesterone." Journal of Endocrinology 114, no. 2 (August 1987): 231–39. http://dx.doi.org/10.1677/joe.0.1140231.
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ABSTRACT The interaction between luteotrophic and luteolytic agents in controlling progesterone production by the marmoset corpus luteum in the late luteal phase/early pregnancy was investigated at the local level in vivo using a perfusion cannula system. Perfusion of the prostaglandin F2α(PGF2α) analogue, cloprostenol (0·5 μg/ml), resulted in an immediate fall in progesterone production. This response was not sustained in two out of five corpora lutea but pregnancy was terminated in all animals exposed to PGF2α. Perfusion of human chorionic gonadotrophin (hCG) (4 μg/ml) alone significantly stimulated progesterone secretion but there was no response to hCG when the corpus luteum had previously been perfused with PGF2α. Perfusion with hCG together with PGF2α prevented a fall in progesterone secretion. The results suggest that the luteolytic action of PGF2α in the marmoset may be to prevent luteotrophic support of the corpus luteum. Melatonin (860 pmol/l), perfused either with PGF2α or after PGF2α, stimulated progesterone production. The ability of melatonin to influence progesterone production by the primate corpus luteum may therefore be by both a direct luteotrophic action and the prevention of luteolysis. Application of the perfusion system in order to investigate the ability of deglycosylated hCG to antagonize the action of hCG at the corpus luteum showed the necessity of testing pure preparations of hormones. J. Endocr. (1987) 114, 231–239
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Bachelot, Anne, Nadège Carré, Olivier Mialon, Melody Matelot, Nathalie Servel, Philippe Monget, Petteri Ahtiainen, Ilpo Huhtaniemi, and Nadine Binart. "The permissive role of prolactin as a regulator of luteinizing hormone action in the female mouse ovary and extragonadal tumorigenesis." American Journal of Physiology-Endocrinology and Metabolism 305, no. 7 (October 1, 2013): E845—E852. http://dx.doi.org/10.1152/ajpendo.00243.2013.
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Transgenic female mice overexpressing the hCGβ subunit (hCGβ+) and producing elevated levels of luteinizing hormone (LH)/hCG bioactivity present as young adults with enhanced ovarian steroidogenesis, precocious puberty, and infertility. They subsequently develop pituitary prolactinomas, high circulating prolactin (PRL) levels, and marked mammary gland lobuloalveolar development followed by adenocarcinomas. None of these phenotypes appear in gonadectomized mice, indicating that the hCG-induced aberrations of ovarian function are responsible for the extragonadal phenotypes. PRL receptor-deficient (PRLR−/−) female mice are sterile, despite ovulating, due to a failure of embryo implantation, as a consequence of decreased ovarian LH receptor (Lhcgr) expression and inadequate corpus luteum formation and progesterone production. To study further the presumed permissive role of PRL in the maintenance of gonadal responsiveness to LH/hCG stimulation, we crossed the hCGβ+ and PRLR−/− mice. The double-mutant hCGβ+/PRLR−/− females remained sterile with an ovarian phenotype similar to PRLR−/− mice, indicating that LH action, Lhcgr expression, and consequent luteinization are not possible without simultaneous PRL signaling. The high frequency of pituitary prolactinomas in PRLR−/− mice was not affected by transgenic hCGβ expression. In contrast, none of the hCGβ+/PRLR−/− females showed either mammary gland lobuloalveolar development or tumors, and the increased mammary gland Wnt-5b expression, possibly responsible for the tumorigenesis in hCGβ+ mice, was absent in double-mutant mice. Hence, high LH/hCG stimulation is unable to compensate for missing PRL signaling in the maintenance of luteal function. PRL thus appears to be a major permissive regulator of LH action in the ovary and of its secondary extragonadal effects.
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Bryant-Greenwood, GD. "Human decidual and placental relaxins." Reproduction, Fertility and Development 3, no. 4 (1991): 385. http://dx.doi.org/10.1071/rd9910385.
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The human placenta and decidua are intrauterine production sites for a range of polypeptide hormones. Relaxin is one of these hormones, its production having been demonstrated by immunocytochemistry and Northern analysis. There are two relaxin genes in the human genome, termed H1 and H2; only the latter is expressed in cyclic and pregnant corpus luteum. However, it has recently been shown that both genes are expressed in the decidua and placenta. It is not known whether both are translated. These hormone(s) may act in a paracrine fashion and be partly responsible for the control of enzymes and inhibitors involved in collagen remodelling in the fetal membranes in the last weeks of pregnancy. An autocrine role of decidual relaxin and a possible decidual-cell/macrophage/extracellular-matrix interaction is described; this may act as a unit in the elaboration of a range of hormones.
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Bramley, T. A., G. S. Menzies, A. S. McNeilly, and H. G. Friesen. "Receptors for lactogenic hormones in the ovine corpus luteum. II: Specific inactivation of ovine prolactin." Journal of Endocrinology 113, no. 3 (June 1987): 375–81. http://dx.doi.org/10.1677/joe.0.1130375.
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ABSTRACT Sheep corpus luteum homogenates and membrane fractions discriminate between 125I-labelled human GH (hGH) and ovine prolactin (oPRL). The present studies were designed to establish whether ovine luteal tissue possessed a prolactin-specific inactivating enzyme. Preincubation of sheep luteal microsomes and cytosol fractions with 125I-labelled hGH had little effect on the ability of the hormone to rebind to pig luteal lactogenic receptors. In contrast, sheep luteal tissue fractions markedly decreased the binding ability of 125I-labelled oPRL. However, despite the profound loss of receptor-binding activity, there was no change in protein-bound radioactivity, nor in the elution profile of 125I-labelled oPRL by gel chromatography on Sephadex G-100. Moreover, the disparity between 125I-labelled hGH and oPRL was not overcome by preincubation of sheep luteal membranes with protease inhibitors of differing specificities. We conclude that the disparity between the binding of hGH and oPRL in ovine tissues was due to the selective inactivation of oPRL. However, the activity responsible did not degrade the hormone extensively, nor was its action blocked by a range of protease inhibitors. J. Endocr. (1987) 113, 375–381
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Bramley, T. A., G. S. Menzies, A. S. McNeilly, and H. G. Friesen. "Receptors for lactogenic hormones in the ovine corpus luteum. I: A major discrepancy in the specific binding of radiolabelled ovine prolactin and human growth hormone." Journal of Endocrinology 113, no. 3 (June 1987): 365–74. http://dx.doi.org/10.1677/joe.0.1130365.
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ABSTRACT The characteristics of the binding of 125I-labelled human GH (hGH) and ovine prolactin (oPRL) were studied in the ovine corpus luteum. Although oPRL is the homologous ligand for sheep lactogenic receptors, its binding was significantly and consistently lower than that of 125I-labelled hGH. This was not due to iodination damage of oPRL since: (1) 125I-labelled oPRL tracers which bound poorly relative to 125I-labelled hGH in the ovine corpus luteum were equipotent in the pig and rat corpus luteum, (2) the differences between 125I-labelled hGH and oPRL binding persisted with tracers of equivalent biopotency and (3) the iodination procedure affected neither oPRL bioactivity in the Nb2 tumour assay nor its binding activity with ovine corpus luteum receptors. Ovine luteal receptors were specific for lactogenic hormones. The specific binding of 125I-labelled hGH or oPRL could be inhibited completely by incubation with either unlabelled hormone, with similar potencies. However, oGH inhibited binding only at much higher concentrations, consistent with its known contamination with oPRL. Moreover, 125I-labelled oGH was not bound specifically to sheep luteal tissue. Fractionation of sheep luteal homogenates on sucrose density gradients (with or without cell-surface membrane perturbation by digitonin) demonstrated that binding of 125I-labelled hGH and 125I-labelled oPRL peaked in the same regions of the gradients, coincident with a number of luteal cell-surface membrane markers. We conclude that the marked discrepancy between the binding of hGH and oPRL tracers by sheep luteal tissue was not due to iodination damage of oPRL, binding of 125I-labelled hGH to somatogenic receptors or differential binding to luteal cell-surface versus intracellular receptors. J. Endocr. (1987) 113, 365–374
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Tsonis, C. G., S. G. Hillier, and D. T. Baird. "PRODUCTION OF INHIBIN BIOACTIVITY BY HUMAN GRANULOSA-LUTEIN CELLS: STIMULATION BY LH AND TESTOSTERONE IN VITRO." Journal of Endocrinology 112, no. 3 (March 1987): R11—R14. http://dx.doi.org/10.1677/joe.0.112r011.
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ABSTRACT Granulosa-lutein cells from human preovulatory ovarian follicles were cultured for up to 12 days to determine their capacity for production of inhibin in vitro. Using a highly sensitive sheep pituitary cell bioassay we observed time-related changes in basal inhibin production, maximal during the first 4 days of culture (48 ± 15 units/million cells every 2 days, means ± S.E.M.; n = 5 patients) falling to values five times lower by day 12. After 4-6 days of culture in the presence of human LH (hLH) inhibin production was enhanced in proportion to the hLH dose (maximum five fold at 10 ng/ml); hFSH over the same dose-range had no effect. Progesterone production in response to hLH followed a similar pattern to that of inhibin and was also unresponsive to hFSH. In the absence of exogenous aromatase substrate, basal and gonadotrophin-stimulated oestradiol production was negligible after the first 4 days. Addition of testosterone (1 μmol/l) to the culture medium increased oestrogen formation several hundredfold with no effect on progesterone production. Inhibin production was also increased by 50-100% in the presence of testosterone. These results demonstrate that LH and testosterone stimulate the production of inhibin by granulosa-lutein cells in vitro. It is suggested that inhibin production occurs under hormonal control in the corpus luteum as well as in the preovulatory follicle in the human ovary.
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Ziecik, Adam J., Emilia Przygrodzka, Beenu M. Jalali, and Monika M. Kaczmarek. "Regulation of the porcine corpus luteum during pregnancy." Reproduction 156, no. 3 (September 2018): R57—R67. http://dx.doi.org/10.1530/rep-17-0662.
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The new corpora lutea (CLs) in pigs are formed from the preovulatory follicles after the luteinizing hormone (LH) surge. However, total autonomy and independence of CLs from LH up to Day 12 of cycle has recently been questioned. Transformation of estrous cycle CL to CL of pregnancy initiated by embryonic signals requires not only the cessation of prostaglandin F2 (PGF2α) supply to the luteal tissue but also needs the CL to overcome luteolytic acquisition and/or changing its sensitivity to PGF2αduring Days 12–14 of pregnancy. The luteolytic cascade is prevented by inhibition of lymphocyte infiltration and leucocyte recruitment, limitation of cell apoptosis, upregulation of pregnancy-associated genes and an enhanced antiluteolytic role of PGE2. Our ‘two-signal switch hypothesis’ highlights the importance ofpostPGF2αand PGE2receptor signaling pathways activation in CLs during luteolysis and rescue. The ‘luteolytic switch’ involves increased expression of many regression mediators and activation of thepostPTGFR signaling pathway. The ‘rescue switch’ initiated by embryonic signals – estradiol 17β and PGE2– inducespostPTGER2/4 pathway, turning the ‘luteolytic switch’ off and triggering activity of genes responsible for CL maintenance. In mid and late pregnancy, CLs are maintained by LH and the synergistic action of metabolic hormones. This paper provides an outline of recent views on CL regression, rescue and maintenance during pregnancy in pigs that conflict with previous paradigms and highlights new findings regarding the actions of prostaglandins, role of microRNAs (miRNA) and immune system and signaling pathways governing the life cycle of porcine CL.
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Dahham, Haddawi M. "Treatment of anoestrus local Iraqi buffaloes (Bubalus bubalis) using different hormones - field study." Iraqi Journal of Veterinary Medicine 38, no. 1 (June 1, 2014): 121–23. http://dx.doi.org/10.30539/iraqijvm.v38i1.264.
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This study aimed to evaluate the efficacy of different hormonal treatments protocols (PGF2α ,GnRH, estradiol and progesterone) hormones on reproductive performance of postpartum anoestrus native dairy River buffaloes (Bubalus bubalis), endemic south of Baghdad under field conditions . Present study was conducted on 128 animals that had postpartum anoestrus (PPA) for a period between 4 to 8 months. The animals were subjected to two experiments according to the type of anoestrus. In the first experiment 94 animals (73.5%) with persistent corpus luteum on their ovaries without any signs of estrous (sub-oestrus) were classified into two sub-groups.Sub-group1 (n=47) treated with PGF2α hormone alone and sub-group 2 (n= 47) were treated by two injections. The first injection was PGF2α. while the second injection GnRH+ PGF2α was injected after 9 days.In second experiment 34 buffalo cows without any structure on their ovaries (True anestrous) were classified into two sub-groups according to design of the treatment. Sub-group 1(n=14) was treated with estradiol as single injection. Sub-Group 2(n=20) received estradiol + progesterone .The results indicated that the pregnancy rate in sub- groups1 and 2 of the first experiment were 85.1% and 89% respectively , which was not significantly differ from each other (P < 0.05). While in the second experiment, the pregnancy rate for the first and second sub- groups were 71% and 75%, respectively. This study concluded that the prevailing situation of anestrous in postpartum buffaloes endemic south of Baghdad is anestrous with corpus luteum (Sub-oestrus) , 94 out of 128 (73.5%) , and the most efficient treatment protocol of these case are PGF2α + GnRH hormones ( pregnancy rate= 89%) . While estradiol + progesterone treatment are efficient in the treatment of animals suffering from true anestrous (pregnancy rate 75%).
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Motta, Jessica C. L., Guilherme Madureira, Lucas O. Silva, Rodrigo L. O. R. Alves, Mayara Silvestri, Jéssica N. Drum, Carlos E. C. Consentini, et al. "Interactions of circulating estradiol and progesterone on changes in endometrial area and pituitary responsiveness to GnRH†." Biology of Reproduction 103, no. 3 (April 30, 2020): 643–53. http://dx.doi.org/10.1093/biolre/ioaa065.
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Abstract Changes in circulating progesterone (P4) and estradiol (E2) during proestrus produce dynamic changes in endometrial function and pituitary release of gonadotropins. Independent and combined effects of P4 and E2 on endometrium and pituitary were evaluated. In a preliminary study, an exogenous hormone model of proestrus was created by removal of corpus luteum and follicles ≥5 mm followed by gradual removal of intravaginal P4 implants during 18 h and treatment with increasing doses of estradiol benzoate during 48 h to mimic proestrus using high E2 (n = 9) or low E2 (n = 9). Decreased P4, increased E2, and increased endometrial area (EA) simulated proestrus in high-E2 cows and this was used subsequently. The main experiment used a 2 × 2 factorial design with: high E2 and low P4 (n = 11); high E2 and high P4 (n = 11); low E2 and high P4 (n = 11); low E2 and low P4 (n = 10). At 48 h, gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) and follicle stimulating hormone (FSH) release was determined. Variables were analyzed using PROCMIXED of Statistical Analysis System. The EA increased dramatically during 48 h only in high-E2 and low-P4 cows. For FSH, high-E2 cows had greater area under the curve (AUC) and FSH peak after GnRH than low E2, with mild negative effects of high P4. For LH, concentration at peak and AUC were 2-fold greater in high E2 compared to low-E2 groups, with low P4 also 2-fold greater than high-P4 groups. Thus, maximal changes in uterus and pituitary during proestrus depend on both low P4 and high E2, but different physiologic responses are regulated differently by E2 and P4. Changes in endometrium depend on low P4 and high E2, whereas GnRH-induced FSH secretion primarily depends on high E2, and GnRH-induced LH secretion is independently increased by high E2 or reduced by high P4.
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H., AL-Anbaky K. I. "A study of Serum Steroid Hormones Concentrations Of Pregnant Cows." Iraqi Journal of Veterinary Medicine 33, no. 1 (June 30, 2009): 180–82. http://dx.doi.org/10.30539/iraqijvm.v33i1.731.
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The objective of present work is to estimated peripheral blood serum concentrations of pregnancyhormones, oestradiol , progesterone and testosterone , in cows . For this purpose 24 Frezain- Holsteincows at different stages of pregnancy the blood samples were taken from jugular veins. The serumwere separated and frozen at – 20 c until analysis. The serum hormones were measured by a specificELISA technique (ELISA Linear Multi Reader). The data were represented Mean + S.D. Progesteronewas high during pregnancy reaching a maximum of 91.94 + 26.09 ng/ml during last thirds (6-8months) of pregnancy , but was below 9.12 + 2.41 ng/ml for several months during the pregnancy.Oestradiol levels varied from 9.0+ 2.89 pg/ml in the first thirds of pregnancy to 282.6 + 48 .514 pg/mlduring the last month of gestation. While testosterone hormone level was low 0.32 + 0.12 ng /mlduring pregnancy. The result indicated that the major sources of hormones appeared to be the 0vary(corpus luteum ) and the uterus (placenta). The ovarian contribution was greater during the first – thirdsof pregnancy than later, whereas that made by the placenta was higher during the last thirds ofpregnancy
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Hapon, María Belén, Alicia B. Motta, Marcelo Ezquer, Melisa Bonafede, and Graciela A. Jahn. "Hypothyroidism prolongs corpus luteum function in the pregnant rat." Reproduction 133, no. 1 (January 2007): 197–205. http://dx.doi.org/10.1530/rep-06-0035.
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It has been shown that hypothyroidism in the rat produces a prolongation of pregnancy associated with a delay in the fall of circulating progesterone (P4) at term. The aim of the present work is to determine whether the delayed P4decline in hypothyroid mother rats is due to a retarded induction of P4degradation to 20αOH P4or to a stimulation of its synthesis, and to investigate the possible mechanisms that may underlie the altered luteal function. We determined by RIA the circulating profile of the hormones (TSH, PRL, LH, P4, PGF2α, and PGE2) involved in luteal regulation at the end of pregnancy and, by semiquantitative RT-PCR, the expression of factors involved in P4synthesis (CytP450scc, StAR, 3βHSD, PRLR) and metabolism (20αHSD, PGF2αR, iNOS and COX2). Our results show that the delay in P4decline and parturition is the resultant of retarded luteal regression, caused by a combination of decreases in luteolytic factors, mainly luteal PGF2α, iNOS mRNA expression and also circulating LH, and increased synthesis or action of luteotrophic factors, such as luteal and circulating PGE2 and circulating PRL. All these changes may be direct causes of the decreased 20αHSD mRNA and protein (measured by western blot analysis) expression, which in the presence of unchanged expression of the factors involved in P4synthesis results in elevated luteal and circulating P4that prolonged pregnancy and also may favor longer survival of the corpus luteum.
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Yang, Ya-Li, Li-Rong Ren, Li-Feng Sun, Chen Huang, Tian-Xia Xiao, Bao-Bei Wang, Jie Chen, Brian A. Zabel, Peigen Ren, and Jian V. Zhang. "The role of GPR1 signaling in mice corpus luteum." Journal of Endocrinology 230, no. 1 (July 2016): 55–65. http://dx.doi.org/10.1530/joe-15-0521.
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Chemerin, a chemokine, plays important roles in immune responses, inflammation, adipogenesis, and carbohydrate metabolism. Our recent research has shown that chemerin has an inhibitory effect on hormone secretion from the testis and ovary. However, whether G protein-coupled receptor 1 (GPR1), the active receptor for chemerin, regulates steroidogenesis and luteolysis in the corpus luteum is still unknown. In this study, we established a pregnant mare serum gonadotropin-human chorionic gonadotropin (PMSG-hCG) superovulation model, a prostaglandin F2α (PGF2α) luteolysis model, and follicle and corpus luteum culture models to analyze the role of chemerin signaling through GPR1 in the synthesis and secretion of gonadal hormones during follicular/luteal development and luteolysis. Our results, for the first time, show that chemerin and GPR1 are both differentially expressed in the ovary over the course of the estrous cycle, with highest levels in estrus and metestrus. GPR1 has been localized to granulosa cells, cumulus cells, and the corpus luteum by immunohistochemistry (IHC). In vitro, we found that chemerin suppresses hCG-induced progesterone production in cultured follicle and corpus luteum and that this effect is attenuated significantly by anti-GPR1 MAB treatment. Furthermore, when the phosphoinositide 3-kinase (PI3K) pathway was blocked, the attenuating effect of GPR1 MAB was abrogated. Interestingly, PGF2α induces luteolysis through activation of caspase-3, leading to a reduction in progesterone secretion. Treatment with GPR1 MAB blocked the PGF2α effect on caspase-3 expression and progesterone secretion. This study indicates that chemerin/GPR1 signaling directly or indirectly regulates progesterone synthesis and secretion during the processes of follicular development, corpus luteum formation, and PGF2α-induced luteolysis.
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Bramley, T. A., and G. S. Menzies. "Specificity studies of particulate binding sites for steroid hormones in subcellular fractions of the porcine corpus luteum." Journal of Endocrinology 136, no. 3 (March 1993): 371–80. http://dx.doi.org/10.1677/joe.0.1360371.
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ABSTRACT We have studied the binding of a number of radiolabelled steroids and lipophilic substances to porcine corpus luteum (CL) particulate fractions. Following preincubation of CL homogenates with radiolabelled progesterone or pregnenolone prior to fractionation on continuous sucrose density gradients, a broad peak of binding was observed associated with a particulate fraction of buoyant density 1·05–1·10 g/cm3. Progesterone content also peaked at a similar buoyant density (1·06–1·12 g/cm3). Pretreatment of luteal homogenates with digitonin perturbed the buoyant density of the progesterone-binding particulate fraction to 1·10–1·14 g/cm3 and sharpened the binding peak. Progesterone content was also perturbed to a similar extent by digitonin pretreatment, without release of the steroid. Oestrogens were also sequestered by this fraction, but steroid precursors (cholesterol, cholesterol ester), corticosteroids (cortisol, corticosterone), sterol conjugates (oestrone sulphate, pregnanediol glucuronide) and other lipophilic substances (arachidonic acid, phospholipid, prostaglandins E1, E2 and F2α) were not bound. Androgens were bound weakly by fractions from control gradients but, in the presence of digitonin, significant binding could be demonstrated. Radiolabelled steroids were shown to interact directly with luteal membrane fractions, rather than interacting first with cytosolic steroid receptors which then bound to membranes. Furthermore, [3H]progesterone was not bound by porcine granulosa cell particulate fractions. These observations suggest that this fraction may be involved in sequestration or packaging of progesterone for secretion by the luteal cell. Journal of Endocrinology (1993) 136, 371–380