Academic literature on the topic 'Ovarian follicular growth'
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Journal articles on the topic "Ovarian follicular growth"
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Zyuzyun, A. B. "CYTOMORPHOLOGICAL RESEARCH OTSYT-CUMULUS COMPLEXES RABBIT FROM WITH OVARIAN AT DIFFERENT STAGES OF THE ESTROUS CYCLE." Animal Breeding and Genetics 53 (April 27, 2017): 279–84. http://dx.doi.org/10.31073/abg.53.39.
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The analysis of the research results revealed that the largest number (86.4%) of oocytes suitable for further development outside the body can be obtained with ovarian follicular phase of growth. It should be noted that statistically significant difference was observed between the groups OCC rabbit derived from ovaries at different phases of the estrous cycle by the number oocytes unsuitable for further cultivation. Thus, the phase of the ovarian follicular growth of gametes was obtained only 13.6% of ovarian and with signs of ovulation and the luteal phase, 35.4% and 31.4% respectively. When comparing the results of the analysis of cytogenetic preparations oocytes from ovaries removed rabbit at different stages of the estrous cycle, found that regardless of the phase of the estrous cycle Yachnik mostly larger number of oocytes were under dyploteny. The largest number of gametes with diffuse chromatin at the stage dyploteny (37.3%) received from the stage ovarian follicular growth. At the stage of fibrillar dyploteny increasing number of gametes was removed from ovarian luteal phase of the estrous cycle. In step dyploteny visible bivalent were more likely gametes obtained from stage ovarian follicular growth (18,1%, p <0,05). The highest percentage of oocytes degeneration chromatin was observed in the group removed from the ovaries to the rabbit lyutealniy phase (21.6%).
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Rak, Agnieszka, and Ewa Gregoraszczuk. "Ghrelin levels in prepubertal pig ovarian follicles." Acta Veterinaria Hungarica 57, no. 1 (March 1, 2009): 109–13. http://dx.doi.org/10.1556/avet.57.2009.1.11.
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Ghrelin is a novel growth hormone-releasing peptide originally identified in the rat stomach as an endogenous ligand of the growth hormone (GH) secretagogue receptor. Recent work suggests that ghrelin plays an important role in reproductive function. In this study, prepubertal pig ovaries were used to examine ghrelin levels in the ovarian follicles. Ghrelin levels in the follicular fluid, follicular wall and culture medium were measured using an enzyme immunoassay (EIA). The ghrelin level in the follicular fluid (18 pg/ml) was the sum of the amounts found in the follicular wall (13.7 pg/ml) and the culture medium (4.6 pg/ml). In conclusion, the data presented in this paper suggest local production of this hormone in ovarian follicles.
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Steckler, Teresa, Jinrong Wang, Frank F. Bartol, Shyamal K. Roy, and Vasantha Padmanabhan. "Fetal Programming: Prenatal Testosterone Treatment Causes Intrauterine Growth Retardation, Reduces Ovarian Reserve and Increases Ovarian Follicular Recruitment." Endocrinology 146, no. 7 (July 1, 2005): 3185–93. http://dx.doi.org/10.1210/en.2004-1444.
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Abstract Exposure to testosterone (T) during d 30–90 of fetal life results in low-birth-weight offspring, hypergonadotropism, multifollicular ovaries, and early cessation of cyclicity. The multifollicular phenotype may result from failure of follicles to regress and consequent follicular persistence or, alternatively, increased follicular recruitment. We tested the hypothesis that prenatal exposure to excess T causes intrauterine growth retardation and increases ovarian follicular recruitment. Time-mated pregnant ewes were treated with 100 mg T propionate in cottonseed oil or vehicle twice weekly from d 30–90 of gestation. Ewes were euthanized near term, from d 139–141 of gestation (term is 147 d). After determining fetal measures and organ weights, ovaries were removed from fetuses of control and T-treated dams, and follicular distribution in each ovary was determined by morphometric quantification. Total number and percentage distribution of the various classes of follicles (primordial, primary, preantral, and antral follicles) were compared between treatment groups. Prenatally T-treated female fetuses were smaller in size, had an increased head circumference to fetal weight ratio (P < 0.01), increased adrenal to fetal weight ratio (P < 0.05), decreased number of follicles (P < 0.05), a decrease in percentage of primordial follicles (P < 0.001), and a corresponding increase in the remaining classes of follicles (P < 0.05). Ovarian findings support decreased ovarian reserve and enhanced follicular recruitment, potential contributors of early reproductive failure. The extent to which metabolic changes associated with intrauterine growth retardation contribute toward altered trajectory of ovarian folliculogenesis remains to be determined.
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CC, Pérez, I. Rodríguez, F. Espańa, J. Dorado, M. Hidalgo, and J. Sanz. "Follicular growth patterns in repeat breeder cows." Veterinární Medicína 48, No. 1 - 2 (March 30, 2012): 1–8. http://dx.doi.org/10.17221/5743-vetmed.
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The aim of this study was to examine follicular development patterns in eighteen repeat breeder cows through natural oestrus cycles. Ovarian ultrasonographic examinations over 32 days after artificial insemination revealed that two follicular waves were the predominant patterns in animals with this syndrome (72.2%). Cycles with one or four waves rarely appeared. The ovulatory follicular diameter (day 0) was larger (P < 0.01) in cycles with a small number of waves; no differences were detected between ovulatory and anovulatory dominant follicles. Progesterone plasmatic concentrations were determined by RIA and differences were not significant when cycles with two or three waves were compared. The number of follicular waves was higher (2 or 3 waves) with longer interovulatory intervals (22.3 ± 1.89 vs 23.0 ± 2.0; n.s.) and older cows (7.0 ± 2.64 vs. 4.38 ± 1.66 years; P < 0.05). Mean ovulatory follicular diameter was 1.78 ± 0.36 cm. It can be concluded that cows with the RBC syndrome more frequently present two follicular waves, corresponding to longer cycles.
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Bachelot, Anne, Philippe Monget, Prune Imbert-Bolloré, Karen Coshigano, John J. Kopchick, Paul A. Kelly, and Nadine Binart. "Growth Hormone Is Required for Ovarian Follicular Growth." Endocrinology 143, no. 10 (October 2002): 4104–12. http://dx.doi.org/10.1210/en.2002-220087.
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Juengel, Jennifer L., Derek A. Heath, Laurel D. Quirke, and Kenneth P. McNatty. "Oestrogen receptor α and β, androgen receptor and progesterone receptor mRNA and protein localisation within the developing ovary and in small growing follicles of sheep." Reproduction 131, no. 1 (January 2006): 81–92. http://dx.doi.org/10.1530/rep.1.00704.
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A first step to elucidating the roles that steroids may play in the processes of ovarian development and early follicular growth is to identify the cell types that are likely to be receptive to steroids. Thus, cell types expressing receptors for oestrogen (α and β form; ERα and ERβ respectively), androgen (AR) and progesterone (PR) were determined by in situ hybridisation and immunohistochemistry in ovine ovarian tissues collected during ovarian development and follicular formation (days 26–75 of fetal life) as well as during the early stages of follicular growth. Expression of ERβ was observed early during ovarian development and continued to be expressed throughout follicular formation and also during the early stages of follicular growth. ERβ was identified in germ cells as well as in the granulosa cells. At the large preantral stage of follicular growth, expression of ERα was also consistently observed in granulosa cells. AR was first consistently observed at day 55 of fetal life in stroma cells throughout the ovary. Within the follicle, expression was observed in granulosa and thecal cells from the type-2 to -3 stage of follicular growth. PR mRNA did not appear to be expressed during ovarian development (days 26–75 of gestation). However, PR (mRNA and protein) was observed in the theca of type-3 (small preantral) and larger follicles, with mRNA – but not protein – observed in granulosa cells of some type-4 and 5 follicles. Expression of ERβ, ERα and AR, as well as PR, was also observed in the surface epithelium and ovarian stroma of the fetal, neonatal and adult ovary. Thus, in sheep, steroid hormones have the potential to regulate the function of a number of different ovarian cell types during development, follicular formation and early follicular growth.
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Juengel, Jennifer L., Norma L. Hudson, Martin Berg, Keith Hamel, Peter Smith, Stephen B. Lawrence, Lynda Whiting, and Kenneth P. McNatty. "Effects of active immunization against growth differentiation factor 9 and/or bone morphogenetic protein 15 on ovarian function in cattle." REPRODUCTION 138, no. 1 (July 2009): 107–14. http://dx.doi.org/10.1530/rep-09-0009.
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Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are essential for ovarian follicular growth in sheep, whereas only GDF9 is essential in mice suggesting that the roles of these oocyte-derived growth factors differ among species. At present, however, there is only limited information on the action of BMP15 and GDF9 in other species. Thus, the aim of this experiment was to determine the effect of neutralizing GDF9 and/or BMP15in vivoon ovarian follicular development and ovulation rate in cattle through active immunization using the mature regions of the proteins or peptides from the N-terminal area of mature regions. Immunization with the BMP15 peptide, with or without GDF9 peptide, significantly altered (increased or decreased) ovulation rate. In some animals, there were no functional corpora lutea (CL), whereas in others up to four CL were observed. From morphometric examination of the ovaries, immunization with GDF9 and/or BMP15 reduced the level of ovarian follicular development as assessed by a reduced proportion of the ovarian section occupied by antral follicles. In addition, immunization against GDF9 and/or BMP15 peptides reduced follicular size to <25% of that in the controls. In conclusion, immunization against GDF9 and BMP15, alone or together, altered follicular development and ovulation rate in cattle. Thus, as has been observed in sheep, both GDF9 and BMP15 appear to be key regulators of normal follicular development and ovulation rate in cattle.
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Dissen, Gregory A., Cecilia Garcia-Rudaz, Alfonso Paredes, Christine Mayer, Artur Mayerhofer, and Sergio R. Ojeda. "Excessive Ovarian Production of Nerve Growth Factor Facilitates Development of Cystic Ovarian Morphology in Mice and Is a Feature of Polycystic Ovarian Syndrome in Humans." Endocrinology 150, no. 6 (March 5, 2009): 2906–14. http://dx.doi.org/10.1210/en.2008-1575.
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Although ovarian nerve growth factor (NGF) facilitates follicular development and ovulation, an excess of the neurotrophin in the rodent ovary reduces ovulatory capacity and causes development of precystic follicles. Here we show that ovarian NGF production is enhanced in patients with polycystic ovarian syndrome (PCOS) and that transgenically driven overproduction of NGF targeted to the ovary results in cystic morphology, when accompanied by elevated LH levels. NGF levels are increased in the follicular fluid from PCOS ovaries and in the culture medium of granulosa cells from PCOS patients, as compared with non-PCOS patients. Ovaries from transgenic mice carrying the NGF gene targeted to thecal-interstitial cells by the 17α-hydroxylase gene promoter produce more NGF than wild-type (WT) ovaries and are hyperinnervated by sympathetic nerves. Antral follicle growth is arrested resulting in accumulation of intermediate size follicles, many of which are apoptotic. Peripubertal transgenic mice respond to a gonadotropin challenge with a greater increase in plasma 17-hydroxyprogesterone, estradiol, and testosterone levels than WT controls. Transgenic mice also exhibit a reduced ovulatory response, delayed puberty, and reduced fertility, as assessed by a prolonged interval between litters, and a reduced number of pups per litter. Sustained, but mild, elevation of plasma LH levels results in a heightened incidence of ovarian follicular cysts in transgenic mice as compared with WT controls. These results suggest that overproduction of ovarian NGF is a component of polycystic ovarian morphology in both humans and rodents and that a persistent elevation in plasma LH levels is required for the morphological abnormalities to appear.
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Fortune, J. E. "Ovarian Follicular Growth and Development in Mammals1." Biology of Reproduction 50, no. 2 (February 1, 1994): 225–32. http://dx.doi.org/10.1095/biolreprod50.2.225.
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Bruno, J. B., J. J. H. Celestino, I. B. Lima-Verde, L. F. Lima, M. H. T. Matos, V. R. Araújo, M. V. A. Saraiva, et al. "Expression of vascular endothelial growth factor (VEGF) receptor in goat ovaries and improvement of in vitro caprine preantral follicle survival and growth with VEGF." Reproduction, Fertility and Development 21, no. 5 (2009): 679. http://dx.doi.org/10.1071/rd08181.
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The aim of the present study was to evaluate the effect of vascular endothelial growth factor (VEGF) on the survival and growth of goat preantral follicles after in vitro culture and to verify the expression of VEGF receptor (VEGFR)-2 in goat ovaries. Ovarian fragments were cultured for 1 or 7 days in minimal essential medium (MEM) with different concentrations of VEGF (1, 10, 50, 100 or 200 ng mL–1). Non-cultured (fresh control) and cultured tissues were processed for histological and ultrastructural studies. The results showed that 200 ng mL–1 VEGF resulted in a similar percentage of normal preantral follicles after 1 and 7 days of culture compared with control. Compared with basic culture medium alone, an increase in follicular and oocyte diameters was observed in the presence of 10 ng mL–1 VEGF after 7 days culture. Ultrastructural analysis confirmed follicular integrity after 7 days culture in the presence of 200 ng mL–1 VEGF. Immunohistochemical studies demonstrated the expression of VEGFR-2 in oocytes and granulosa cells of all follicular stages, except in granulosa cells of primordial follicles. In conclusion, the present study has shown that VEGF maintains follicular ultrastructural integrity and promotes follicular growth. In addition, VEGFR-2 is expressed in oocytes of caprine ovarian follicles at all developmental stages and in granulosa cells of developing follicles.
Dissertations / Theses on the topic "Ovarian follicular growth"
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Bracken, Cynthia J. "Factors controlling ovarian follicular growth in sows /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3115527.
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Hampton, James Howard. "Luteinizing hormone modulation of bovine ovarian follicular growth, selection and pathology /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3101022.
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Commin, Loris. "Cryoconservation du tissu ovarien et production d’embryons chez la chienne." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10116.
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De nos jours, la cryoconservation est une technique très largement utilisée dans les protocoles d’assistance à la reproduction ou comme outil pour la sauvegarde des ressources génétiques. Toutefois, la chienne est un modèle animal complexe pour l’application des biotechnologies de la reproduction du fait de ses nombreuses singularités anatomiques et physiologiques. L’objectif de notre travail était d’étudier et de développer une méthode de cryoconservation des ressources génétiques chez la chienne par le biais de deux types de ressources : les embryons et le tissu ovarien. Après avoir mis au point une méthode de collecte d’embryons, nous nous sommes appliqués à la constitution d’un stock d’embryons cryoconservés en prévision d’un transfert embryonnaire. L’étude et le développement d’un protocole de cryoconservation du tissu ovarien ont été abordés après avoir adapté et validé nos méthodes d’analyses in vitro. L’utilisation de plans d’expériences factoriels fractionnaires a permis de mettre en évidence les facteurs les plus influents sur la qualité de la réserve folliculaire (nature du cryoprotecteur pénétrant, cinétique de congélation, étapes d’équilibration) et de proposer un protocole de cryoconservation. La combinaison du DMSO incorporé en un seul bain d’équilibration avec une vitesse de congélation de 0,3°C/min est apparue comme la combinaison la plus appropriée à la cryoconservation de tissu ovarien chez la chienne et a permis d’observer, après xénogreffe de tissu ovarien cryoconservé, une reprise de la croissance folliculaire et de l’activité hormonale du tissu grefféNowadays, cryopreservation is widely used in animal assisted reproduction or safeguarding of genetic resources. Nevertheless, the bitch is a complex animal model concerning the use of this biotechnology, due to numerous anatomical and physiological peculiarities. The aim of our research work was to investigate and develop a method of cryopreservation of genetic resources in the bitch by exploring two kinds of resources: embryos and ovarian tissue. After the setting up of a method for embryo collection, we have built up a stock of cryopreserved embryo for subsequent embryo transfer. After a preliminary validation of our in vitro assessment methods, the investigation and development of a cryopreservation protocol has been conducted. The use of fractional experimental design allowed us to highlight the main factors affecting the follicular pool quality (CPA nature, freezing rate and equilibration steps). The combination of DMSO incorporated in a unique equilibration bath with a freezing rate of 0.3°C/min appeared to be suitable for the cryopreservation of bitch ovarian tissue. Finally, Follicular growth and hormonal activity resumption have been observed after xenotransplantation of cryopreserved bitch ovarian tissue
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Wright, Rebecca Jane. "Insulin-like growth factor binding proteins as co-ordinators of human ovarian follicular function." Thesis, St George's, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404588.
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Lundberg, Allie Lynn. "Investigation Of Transforming Growth Factor-Alpha And Its Potential Role In Promoting Ovarian Follicular Dominance." ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1136.
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Intraovarian growth factors play a vital role in influencing the fate of ovarian follicles. They affect proliferation versus apoptosis of granulosa cells (GCs), and can influence whether small antral follicles continue their growth or undergo atresia. Transforming Growth Factor-alpha (TGFα), an oocyte-derived growth factor, is thought to regulate granulosa cell function, yet has been largely overshadowed by current interest in TGF-beta superfamily members, such as bone morphogenetic proteins (BMPs) and anti-Mullerian hormone (AMH). In the current study, effects of TGFα on bovine GC proliferation, intracellular signaling and cytokine-induced apoptosis were evaluated. Briefly, all small antral follicles (3-5mm) from bovine ovaries were aspirated and the cells were initially plated in T25 flasks containing DMEM/F12 medium, 10% FBS, and antibiotic-antimycotic, and incubated at 37 degrees Celsius in 5% CO2 for 3-4 days. Once confluent, the cells were sub-cultured to 96-, 12- or 6-well plates in serum-free conditions (insulin 100 ng/mL; transferrin 55 ng/mL; sodium selenite 6.7 pg/mL). 24-hour treatment of bovine GCs with TGFα (10 and 100ng/mL) stimulated cell proliferation compared to control (p<0.05; n = 7 ovary pairs). Cell proliferation was accompanied by a concomitant increase in mitogen-activated protein kinase (MAPK) signaling within 2 hours of treatment, as measured by phosphorylated ERK1/2 expression (p<0.05, n = 3 ovary pairs). These effects were entirely negated, however, by the MAPK inhibitor, U0126 (10uM, p<0.05). Additionally, pre-exposure of the bovine GCs to TGFα (100ng/mL) failed to prevent Fas Ligand (100ng/mL)-induced apoptosis, as determined by caspase 3/7 activity (P<0.05, n = 7 ovary pairs). Collectively, the results indicate TGFα stimulates proliferation of bovine GCs from small antral follicles via a MAPK/ERK-mediated mechanism, but this action alone fails to prevent apoptosis, suggesting TGFα may be incapable of promoting the persistence of follicles during the process of follicular selection and deviation.
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Schauer, Stephanie Nicole. "Role of luteinising hormone in ovarian follicle development and maturation in the mare." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/11731.
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Luteinising hormone (LH) is a crucial regulator of ovarian follicle maturation, ovulation and luteinisation. Development of healthy follicles and fertile ovulation can only occur within a specific range of circulating LH concentrations, with differing upper and lower limits depending on the stage of the oestrous cycle. The objective of the three studies in this thesis was to investigate the effects of both physiological and non-physiological circulating LH levels on equine follicular maturity by examining ovulatory and steroidogenic capacity, gene expression profiles and miRNA expression in ovulatory-size follicles at various stages of the oestrous cycle and/or in response to supplementation with LH. The aim of the first study was to investigate the hypothesis that deficient circulating LH is a primary cause for the inability of equine follicles to ovulate during the physiological anovulatory season. A LH-rich equine pituitary fraction (eLH) given twice daily to early transitional mares did not restore steroidogenic capacity of the ovulatory-size follicle or advance the onset of the natural breeding season; however, it significantly stimulated follicular growth to a level similar to that occurring during the normal oestrous cycle. The results demonstrated that a deficiency in LH is critically involved in reduced follicle growth during the anovulatory season. The second study examined the effects of elevated circulating LH levels early during follicle development on follicle maturation and ovulatory ability in cycling mares, with the hypothesis that excessive LH would disrupt ovulation and produce haemorrhagic anovulatory follicles (HAFs). Treatment with eLH or a luteolytic dose of prostaglandin F2α (to stimulate an increase in endogenous levels of LH) did not have any effects on follicle growth or ovulation, but did impair follicular production of androstenedione and insulin-like growth factor 1 (IGF1), suggesting a deleterious effect of high LH on follicle and oocyte maturation. The third study examined the expression of different follicular factors associated with follicle maturation as well as microRNAs (miRNAs) in ovulatory-size follicles naturally developing under different LH milieus (oestrus, dioestrus and spring transitional period). Progesterone and IGF1 were significantly reduced in follicles developing in a low LH environment (dioestrus and transition). All four miRNAs measured, miR-378, miR-542, miR-202 and miR-21 were found at higher levels in subordinate follicles than in preovulatory follicles during oestrus. In addition miR- 202 and miR-21 were significantly increased in transitional follicles relative to oestrous follicles. The results of this study indicate that follicles developing during both the spring transitional and dioestrous periods are developmentally immature and suggested potential important roles of miRNAs in follicle maturation in the horse. In summary, although LH is a key factor promoting follicular growth, it is by itself not sufficient to restore steroidogenic activity in transitional follicles. Elevated LH levels during follicle development do not disrupt ovulation, but induce changes in follicular fluid factors related to follicle maturation and oocyte quality. Follicles developing under different LH milieus show altered miRNA expression, suggesting an important role of miRNAs in follicle maturation.
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Gong, Jin Gui. "The role of growth hormone, insulin-like growth factor-I and insulin in the control of ovarian follicular growth and development in the heifer." Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/19802.
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Recent experimental evidence has suggested that the control of ovarian folliculogenesis and ovulation rate in cattle cannot be accounted for solely through changes in pituitary gonadotrophins, gonadal steroids and/or proteins. The aim of this project was to investigate the role of growth hormone (GH), insulin-like growth factor-I (IGF-I) and insulin in the control of ovarian follicular growth and development in heifers. Daily treatment of heifers with 25mg recombinant bovine somatotropin (BST), for a period of 2 oestrous cycles, significantly increased the population of small ovarian follicles (2-5mm in diameter) although ovulation rate ws unaltered. While peripheral concentrations of GH, IGF-I and insulin were significantly increased, there was no effect of BST on either circulating concentrations of oestradiol, progesterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) or number of FSH and LH binding sites in granulosa and thecal cells. A further study using real-time ultrasound demonstrated that in our population of heifers the majority (9/12) have 3 waves of follicular growth and development per oestrous cycle, whilst the remainder displayed a 2-wave pattern. The growth of each dominant follicle was always associated with a marked reduction in the number and growth of the subordinate follicles. While there was no effect of BST on both the number of follicular waves and the number of large (> 10mm) and medium-sized (5-10mm) follicles, BST treatment significantly increased the number of small follicles throughout the treatment period. However, the inhibitory effect of the dominant follicle on subordinate follicles was not affected by BST treatment. Treatment of heifers with a single dose of BST (320mg in a sustained release formulation) demonstrated that the increase in the number of small follicles was temporally correlated with changes in peripheral IGF-I and insulin concentrations.
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Meikle, Ana. "Reproductive endocrinology of prepubertal and anestrous ewes : regulation of uterine sex steroid receptors by ovarian hormones and effects of estradiol on gonadotropin secretion and follicular growth /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-5915-X.pdf.
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Mazerbourg, Sabine. "La proteolyse de l'insulin-like growth factor binding protein-4 (igfbp-4) dans les follicules ovariens chez les mammiferes domestiques : identification de la protease, etude de sa regulation, consequences sur la maturation folliculaire." Paris 6, 2000. http://www.theses.fr/2000PA066319.
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Les igfs (insulin-like growth factors) jouent un role crucial dans le developpement folliculaire en amplifiant l'action des hormones gonadotropes hypophysaires, fsh et lh. Leur action stimulante est modulee par la presence de proteines de liaison, les igf-binding proteins (igfbps), dans le liquide folliculaire. Chez la brebis, la vache, la truie, la jument et la femme, la croissance et l'atresie folliculaire sont associees respectivement a une diminution et a une augmentation des teneurs en igfbp-4 dans le liquide folliculaire. Ces variations sont essentiellement dues a des variations de l'activite proteolytique capable de la degrader. Les objectifs de notre travail ont ete 1) d'identifier la protease responsable de la degradation proteolytique de l'igfbp-4 dans les follicules preovulatoires ; 2) de determiner les mecanismes locaux de regulation de l'activite proteolytique ; 3) de rechercher le role biologique des fragments de proteolyse de l'igfbp-4 dans la maturation folliculaire. Nous avons montre que la pregnancy-associated plasma protein-a (papp-a) est la metalloprotease impliquee dans la degradation de l'igfbp-4 dans les follicules preovulatoires de brebis, de vache, de truie et de jument. Chez la truie et la vache, l'expression des arnms de la papp-a dans les cellules de granulosa est etroitement correlee a celle de l'aromatase et des recepteurs a lh. Elle est maximale dans les follicules preovulatoires et faible, mais non nulle, dans les follicules atretiques et dans les follicules immatures. Au niveau post-traductionnel, l'igf-i potentialise la proteolyse de l'igfbp-4 par la papp-a. A l'inverse, les igfbp-2 et -3 ainsi que des peptides de liaison a l'heparine derives du domaine carboxy-terminal de l'igfbp-3 ou -5 ou du ctgf (connective tissue growth factor), du hip (heparan/heparin interacting peptide) et de la vitronectine inhibent la degradation de l'igfbp-4 par le liquide folliculaire de follicules preovulatoires. Ces effets passent par une reduction de la biodisponibilite intrafolliculaire des igfs et/ou par une interaction directe avec la papp-a par l'intermediaire du domaine de liaison a l'heparine. Enfin, in vitro, des resultats preliminaires montrent un effet potentialisateur des fragments carboxy-terminaux de l'igfbp-4 sur la production de progesterone par les cellules de granulosa ovines cultivees en presence d'igf-i, suggerant que la degradation proteolytique de l'igfbp-4 aboutit a une amplification de l'action de l'igf-i en participant a l'augmentation de sa biodisponibilite et en potentialisant son action au niveau cellulaire.
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(9874766), JL Vaughan. "Control of ovarian follicular growth in the alpaca, Lama pacos." Thesis, 2001. https://figshare.com/articles/thesis/Control_of_ovarian_follicular_growth_in_the_alpaca_Lama_pacos/13424564.
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The aim of the studies in this thesis was to develop a treatment protocol that controlled ovarian follicular growth so that the time of optimum fertility could be predicted in female alpacas.
Female alpacas exhibit growth and regression of successive large follicles and typically only ovulate in response to the mating stimulus. Non-pregnant females are sexually receptive most of the time, apparently regardless of the stage of ovarian follicular growth. Conventional breeding
results in slow genetic gain because matings occur at random stages of follicular development. Because of the nature of their reproductive physiology, assisted breeding technologies are poorly developed in alpacas and the Australian alpaca industry relies on transport of males and females over relatively large distances to disseminate superior genotypes. The efficiency of this form of genetic improvement would be enhanced if conception rates to a single mating could be increased.
Initial studies in this thesis aimed to clarify ovarian follicular growth characteristics in nonpregnant females. An inverse relationship between the diameter of the largest follicle and the number of follicles detected supports the hypothesis that follicular growth in camelids occurs in
waves. It was established that the growth characteristics of follicular waves varied within and between females. Wide variation in the interval between successive follicular waves made the use of a mean interwave interval value inappropriate. Non-pregnant alpacas had a follicle in the size range potentially capable of ovulating, but of unknown fertility, on either ovary most of the time.
A second objective was to determine the relationships between sexual receptivity, mating behaviour, ovarian follicular state and mating success. It was not possible to correlate mating behaviour or ovarian status with mating success. Matings to optimise pregnancy rates in alpacas need to occur in the presence of an oestrogenic follicle that is capable of ovulation in response to mating. Simple detection of alpacas with follicles in this state was not possible and treatments to control ovarian follicular growth were therefore investigated.
Attempts to control ovarian follicular waves in alpacas were focussed on inducing regression of the existing dominant follicle of unknown age and allowing emergence of a new cohort of follicles at a known time after treatment. The induction of ovulation to remove the existing dominant follicle was not considered in these studies. Single intramuscular (i.m.)
injections of 1713-oestradiol (oestradiol) or oestradiol benzoate, at different doses and with and without simultaneous injection of progesterone, were unsuccessful in controlling follicular growth
to allow emergence of a new follicular wave at a known time. This finding was unexpected given that oestradiol causes the regression of follicles in cattle and sheep. It was concluded that alpacas, and perhaps camelids in general, have different intra- and/or extra-ovarian mechanisms that control follicular growth and regression compared with ruminants that are spontaneous ovulators.
Subsequent studies examined the effects of different protocols of progesterone treatment on ovarian follicular growth and regression. Twice daily i.m. injection of25 mg of progesterone for 21 days was effective at inducing regression of the existing dominant follicle and suppressing emergence of a new follicular wave until treatment ceased. To make the treatment more practical and reduce the number of injections required, subcutaneous implants of norgestomet and lower
frequency, higher dose progesterone treatments were examined. The most practical and effective protocol for ovarian follicular control in female alpacas was provided by 200 mg progesterone injected i.m. on Days 0, 2 and 4. The majority of females treated with this protocol had a newlyemerged follicle with a diameter capable of ovulation on Day 16, 12 days after progesterone
treatment ceased. Mating trials were performed on three commercial alpaca farms to compare pregnancy rates at Day 60 in females treated with the progesterone protocol and mated on Day 16 and females mated at random. Results showed that treated females were capable of ovulation, fertilisation and pregnancy, however, there was no difference in 60-day pregnancy test percentage between females receiving the Day 0-4 progesterone synchronisation protocol and females treated with oil placebo.
The oocyte contained in the first dominant follicle following progesterone treatment would need to be of normal fertility in order for the progesterone-based protocol to increase pregnancy rates to a single mating. As a first step to examining oocyte integrity, oocytes were retrieved by ultrasound-guided, transvaginal aspiration on Day 17 in females treated with the progesterone protocol described above involving injections on Days 0, 2 and 4. Half of these females had an injection ofluteinising hormone (LH) on Day 16 to simulate a mating-induced LH
surge. Oocytes were examined by light and electron microscopy to observe whether the cellular ultrastructure was indicative of normal maturation. Only oocytes from those females that received LH showed changes to the cellular ultrastructure indicative of normal maturation including meiotic progression (nuclear maturation) from Prophase I to Metaphase I, an increase in the width of the perivitelline space and expansion of the cumulus cells surrounding the oocyte. This finding was
interpreted to suggest that the oocyte contained in the first ovulatory follicle after progesterone treatment has a normal capacity for fertilisation and embryo development competency.
This thesis presents new information on ovarian follicular wave characteristics in nonpregnant female alpacas and introduces a practical protocol based on progesterone to control ovarian follicular growth. The protocol allows for fixed-time mating. The Australian alpaca industry will benefit from more efficient utilisation of genetically superior males and females and faster dissemination of improved genotypes throughout the national herd. Potential benefits include incorporation of the progesterone protocol into other assisted breeding technologies such as artificial insemination, embryo transfer and possibly the in vivo maturation of oocytes for in vitro fertilisation.
Books on the topic "Ovarian follicular growth"
1
International Symposium on Molecular and Clinical Aspects of the Regulation of Ovarian Function: Impact on the Reproductive Health of Women (1999 New Delhi, India). Follicular growth, ovulation, and fertilization: Molecular and clinical basis. Edited by Mukhopadhyay Amal K. New Delhi: Narosa Pub. House, 2001.
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2
W, Shaw Robert, ed. The Control and stimulation of follicular growth. Carnforth, Lancs., UK: Parthenon Pub. Group, 1993.
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3
Lucy, Matthew Christian. Effects of calcium salts of long-chain fatty acids, growth factors, and energy balance on ovarian follicular dynamics in postpartum dairy cows. 1990.
Find full textBook chapters on the topic "Ovarian follicular growth"
1
Moley, Kelle H., and James R. Schreiber. "Ovarian Follicular Growth, Ovulation and Atresia." In Advances in Experimental Medicine and Biology, 103–19. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4899-0952-7_7.
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Ryan, Kenneth J., and Anastasia Makris. "Significance of Angiogenic and Growth Factors in Ovarian Follicular Development." In Advances in Experimental Medicine and Biology, 203–9. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4684-5395-9_10.
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Gelen, Volkan, Emin Şengül, and Abdulsamed Kükürt. "An Overview of Effects on Reproductive Physiology of Melatonin." In Melatonin - Recent Updates [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.108101.
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Melatonin is a neurotransmitter released from the pineal gland. The presence of receptor sites in the hypothalamus, pituitary gland, ovaries, and testicles and secretion of pituitary hormones (FSH and LH) are some of the effects of this hormone on reproduction. In addition to its systemic effect, it also showed an effect on ovarian physiology with the detection of high levels in the follicular fluid and the presence of melatonin receptors in the ovarian cells. In addition, it has been determined that melatonin affects follicular growth, oocyte maturation, ovulation, and luteal function. It has been stated that the effects of melatonin on the male reproductive system are indirectly effective through the gonads and indirectly by affecting the hormones. Again, some studies have expressed that melatonin has strong antioxidant properties and affects reproductive physiology due to this effect. This section discusses the effect of melatonin on male and female reproductive physiology.
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ATA, Baris, Ayse Seyhan, and Seang Tan. "Applicability and reproducibility of sonography-based automated volume count (Sono AVC) in monitoring follicular growth." In Manual of Ovulation Induction and Ovarian Stimulation Protocols, 632. Jaypee Brothers Medical Publishers (P) Ltd., 2016. http://dx.doi.org/10.5005/jp/books/12832_68.
Full textReports on the topic "Ovarian follicular growth"
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Wolfenson, David, William W. Thatcher, and James E. Kinder. Regulation of LH Secretion in the Periovulatory Period as a Strategy to Enhance Ovarian Function and Fertility in Dairy and Beef Cows. United States Department of Agriculture, December 2003. http://dx.doi.org/10.32747/2003.7586458.bard.
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The general research objective was to increase herd pregnancy rates by enhancing corpus luteum (CL) function and optimizing follicle development, in order to increase conception rate and embryo survival. The specific objectives were: to determine the effect of the duration of the preovulatory LH surge on CL function; to determine the function of LH during the postovulatory period on CL development; to optimize CL differentiation and follicle development by means of a biodegradable GnRH implant; to test whether optimization of CL development and follicle dynamics in timed- insemination protocols would improve fertility in high-yielding dairy cows. Low fertility in cattle results in losses of hundreds of millions of dollars in the USA and Israel. Two major causes of low fertility are formation of a functionally impaired CL, and subsequent enhanced ovarian follicle development. A functionally impaired CL may result from suboptimal LH secretion. The two major causes of low fertility in dairy cattle in US and Israel are negative energy status and summer heat stress; in both situations, low fertility is associated with reductions in LH secretion and impaired development of the ovulatory follicle and of the CL. In Florida, the use of 450-mg deslorelin (GnRH analogue) implants to induce ovulation, under the Ovsynch protocol resulted in a higher pregnancy rates than use of 750-mg implants, and pregnancy losses tended to decrease compared to controls, due probably to decrease in follicular development and estradiol secretion at the time of conceptus signaling to maintain the CL. An alternative strategy to enhance progesterone concentrations involved induction of an accessory CL by injection of hCG on day 5 after the cows were inseminated. Treatment with hCG resulted in 86% of the cows having two CLs, compared with 23% of the control cows. Conception rates were higher among the hCG-treated cows than among the controls. Another approach was to replace the second injection of GnRH analogue, in a timed-insemination protocol, with estradiol cypionate (ECP) injected 24 h after the injection of PGF₂ₐ Pregnancy rates were comparable with those obtained under the regular Ovsynch (timed- AI) program. Use of ECP induced estrus, and cows inseminated at detected estrus are indeed more fertile than those not in estrus at the time of insemination. Collectively, the BARD-supported programs at the University of Florida have improved timed insemination programs. In Ohio, the importance of the frequency of LH episodes during the early stages of the estrous cycle of cattle, when the corpus luteum is developing, was studied in an in vivo experiment in which cows were subjected to various episodic exposures to exogenous bovine LH. Results indicate that the frequent LH episodes immediately following the time of ovulation are important in development of the corpus luteum, from the points of view of both size and functionality. In another study, rates of cell proliferation and numbers of endothelial cells were examined in vitro in CLs collected from cows that received post-ovulation pulsatile LH treatment at various frequencies. The results indicate that the corpora lutea growth that results from luteal cell proliferation is enhanced by the episodes of LH release that occur immediately after the time of ovulation in cattle. The results also show that luteal endothelial cell numbers did not differ among cows treated with different LH doses. In Israel. a longer duration of the preovulatory LH surge stimulated the steroidogenic capacity of granulosa-derived luteal cells, and might, thereby, contribute to a higher progesterone output from the bovine corpus luteum. In an in vivo study, a subgroup of high-yielding dairy cows with extended estrus to ovulation interval was identified. Associated with this extended interval were: low plasma progesterone and estradiol concentrations and a low preovulatory LH surge prior to ovulation, as well as low post- ovulation progesterone concentration. In experiments based on the above results, we found that injection of GnRH at the onset of estrus increased the LHpeak, prevented late ovulation, decreased the variability between cows and elicited high and uniform progesterone levels after ovulation. GnRH at estrus onset increased conception rates, especially in the summer, and among primiparous cows and those with low body condition. Another study compared ovarian functions in multiparous lactating cows with those in nulliparous non-lactating heifers. The results revealed differences in ovarian follicular dynamics, and in plasma concentrations of steroids and gonadotropins that may account for the differences in fertility between heifers and cows.