Academic literature on the topic 'Buserelin acetate'

The seminal plasma (SP) of camelids contains a protein identified as β Nerve Growth Factor with capacity of induced ovulation and develop a corpus luteum. A study was designed to evaluate the effect of application of SP on the interval of time from injection of stimulus to the ovulation and corpus luteum (CL) size (Experiment 1, n = 24) and on the sensitivity of CL to the injection of prostaglandin (196 µg of tiaprost) (PG) at different periods from ovulation (Experiment 2, n = 86). Exp. 1: Adult female alpacas with presence of a follicle ≥7 mm were assigned to the application of 1 mL of SP via IM (T: n = 12) or application of 50 µg of acetate of busereline IM (T2: n = 12). Exp. 2: Alpacas with presence of a follicle ≥7 mm were induced to ovulation with 50 µg of acetate of busereline or 1 mL IM of SP. Animals were evaluated by ultrasound to confirm the ovulation and were assigned to the following treatment: T1 (n = 8): SP + PG Day 4; T2 (n = 8): buserelin acetate + PG Day 4; T3 (n = 8): SP + PG Day 5; T4 (n = 8): buserelin acetate + PG Day 5; T5 (n = 8): SP + PG Day 6; T6 (n = 8): buserelin acetate + PG Day 6; T7 (n = 8): SP + PG Day 7; T8 (n = 8): buserelin acetate + PG Day 7; T9 (n = 8): SP + PG Day 8; T10 (n = 8): buserelin acetate + PG Day 8 and T11 (n = 6) (Control): Application of 1 mL of saline solution. The animals were evaluated by ultrasound with an Aloka SSD500 (Aloka, Tokyo, Japan) and 7.5-MHz linear transducer each 2 h (Exp. 1) and each 12 h (Exp. 2) after of application of PG. In Exp. 1, the ovulation rate was 95.7% to T1 and T2 and an interval of time between injection of stimulus and ovulation was 27.4 ± 2.5 h and 26.8 ± 1.8 to T1 and T2, respectively. In Exp. 2, luteolysis was 0.0%, 0.0%, 25.0%, 0.0%, 100.0%, 100.0%, 100.0%, 100.0%, 100.0%, 100.0%, and 0.0% for the treatments T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, and T11 respectively. The results suggest that no differences exist between in the ovulation rate and interval to the ovulation between the application of buserelin acetate or SP and that the CL was sensible at Day 5 to the prostaglandin respect SP and with similar response to the sensibility of CL from Day 6 to Day 8.

Background: Both biodegradable and non-biodegradable peptide-loaded implants are already developed for the long-term treatment of patients, thereby reducing the frequency of drug administration. To further improve peptide formulation, extending the scope of implant-based drug delivery systems towards other polymers and processing techniques is highly interesting. Objective: In this study, as a proof-of-principle, the feasibility of hot-melt processing of a peptide active pharmaceutical ingredient was assessed by developing a non-biodegradable poly(ethylenevinyl acetate) (33% VA) implant loaded with 20% (w/w) buserelin acetate. Methods: Cross-sectional implant characterization was performed by Raman microscopy. The stability of buserelin acetate in the polymeric matrix was evaluated for 3 months under ICH stability conditions and the quantity as well as the degradation products analyzed using LC-UV methods. An in vitro dissolution study was performed as well and buserelin acetate and its degradants analyzed using the same chromatographic methods. Results: No significant quantities of buserelin acetate-related degradation products were formed during the hot-melt preparation as well as during the stability study. Together with the consistent buserelin acetate assay values over time, chemical peptide stability was thus demonstrated. The in vitro buserelin acetate release from the implant was found to be diffusion-controlled after an initial burst release, with stable release profiles in the stability study, demonstrating the functional stability of the peptide implant. Conclusion: These results indicate the feasibility of preparing non-biodegradable peptide-loaded implants using the hot-melt production method and may act as a proof of principle concept for further innovation in peptide medicinal formulations.

ABSTRACT In women with endometriosis there is concern that therapeutic use of LH-releasing hormone (LHRH) analogues, to lower ovarian oestrogen production and control endometrial hyperplasia, leads to unwanted oestrogen-deficiency bone loss. We have developed an animal model of this LHRH-mediated oestrogen-deficiency bone loss in the rat, using buserelin. The aim was to use this model to determine whether the progestogen, norethindrone acetate, could counter oestrogen-deficiency bone loss associated with prolonged treatment with the LHRH agonist buserelin. Four groups of animals which had their bones labelled with 45Ca were studied for 4 weeks: group A, control; group B, buserelin treated; group C, norethindrone acetate treated; group D, norethindrone acetate + buserelin treated. Buserelin was given daily (19·2 pmol/kg body wt); norethindrone was given orally three times / week (1·47 μmol/kg body wt). Bone resorption was monitored by measuring the urinary excretion of hydroxyproline and 45Ca and bone 45Ca content. Buserelin-treated rats developed similarly depressed plasma oestradiol-17β values in the presence and absence of progestogen, and both groups given buserelin had significantly smaller uteri than controls or rats given norethindrone without buserelin. However, norethindrone did not prevent buserelin-mediated increases in bone resorption. At the end of the study total body calcium values (mean ± s.d.) in the four groups were (mg) respectively; 2594 ± 123; 2260 ± 92 (P < 0·001 compared with controls); 2616 ± 221; 2415 ± 130 (P < 0·02 compared with controls). Rats given norethindrone and buserelin in combination had higher values (P < 0·02) than animals given buserelin alone, but significantly less total body calcium than controls (P < 0·02). We conclude that progestogen confers partial, but not complete, protection of the skeleton of buserelin-treated rats from oestrogen-deficiency bone loss. Journal of Endocrinology (1993) 137, 27–33

ABSTRACTHigh milk production, heat, physiological status and management impair reproduction in Holstein cows. The use of in vivo-produced embryos has been reported as an alternative to enhance pregnancy outcome in the tropics; however there are several limitations for its production, especially from variations in superovulatory responses. The in vitro production of embryos would avoid such variations, but few studies have been reported. This study aims to verify the effects of variables related to recipients under a program of routine in vitro embryo transfer on a commercial dairy farm in southeastern Brazil. It was hypothesized that pregnancy rates after transfer of ovum pick up or OPUderived embryos (ET) to lactating Holstein recipients may be influenced by recipient GnRH-treatment at ET, parity, milk production and body condition score. Recipients (267) were allocated to one of three i.m. treatments given at ET: Control (92) - 2.5 ml saline; Buserelin (86) - 10 μg Buserelin acetate; Deslorelin (89) - 750 μg Deslorelin acetate. Ultrasound images and blood samples were taken at ET and seven days later. The first pregnancy diagnosis was performed between 30-40 days and the second between 60-80 days post ET. Data were analyzed by GENMOD (SAS(r)). The proportion of pregnant cows was greater (P&lt;0.05) in Buserelin-treated recipients (38.3%) at the first pregnancy diagnosis than Controls (24.1%), but similar to Deslorelin and control cows at the second diagnosis (13.0, 20.9 and 14.6% in Control, Buserelin and Deslorelin, respectively). In conclusion, Buserelin improved pregnancy rate only transitorily, under the present conditions.

The productivity of rabbit farms can be increased and become more homogeneous through the use of Artificial Insemination (AI). However, this possibility is limited with low conception in artificially inseminated does without ovulation induction. This study aimed at determining the conception rate of rabbit does induced with buserelin acetate and inseminated with extended semen at varied dilution ratio. A total number of Twenty eight multiparous non-lactating rabbit does were randomly allotted into four treatments housed individually in a completely randomised design. Rabbits were used as a teaser for semen collection using an artificial vagina and after semen collection and evaluation; ejaculates from ten bucks with more than 60% motility were pooled and extended. Forty eight hours before the AI, the does were hormonally synchronized (i.m) for oestrus with 20IU PMSG. Does in treatment 1(control) were inseminated with unextended semen without buserelin but injected with normal saline, while does on treatments 2, 3 and 4 were inseminated with extended semen in ratio 1: 1, 1:2 and 1: 3 (semen: extender), respectively and were all intramuscularly induced using 0.8µg of buserelin after insemination. Results showed that some of the does induced with buserelin acetate intramuscularly (treatments 2, 3 and 4) were pregnant, while none of the control rabbits was pregnant. The ratio 1: 1 extended semen (treatment 2) recorded the highest percentage conception (85.71%) followed by treatment 3 (71.43%) and treatment 4 (57.14%). There was significant (P<0.05) difference in gestation length (32.50, 31.00 and 32.75), litter size (4.83, 8.60 and 3.25), live kits at birth (3.50, 6.60 and 1.75) for treatments 2, 3 and 4 respectively and the average litter weight was not significantly different among the treatments. This study suggests that diluting semen in ratio 1: 1 produced highest conception rate with intramuscular administration of 0.8µg buserelin acetate than extending semen in ratios 1: 2 and 1: 3.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
This study was carried out at Agropecuária Paraíso, Santa Teresa, ES - Brazil, with the objective to evaluate the effect of the injection of buserelin acetate (BA), an analogue of GnRH, on the fertility of heifers and lactating cows. Eighty two animals, 20 heifers and 62 cows, ½ Holstein/Zebu crossbred to Holstein P.O., were distributed in a completely random design experiment, with four treatments, as follows: T1 - control treatment (5 heifers and 16 cows), received 2.5 mL of physiological solution (SF), intramuscularly (i.m.), at the artificial insemination time (A.I.; d 0); T2 - (5 heifers and 15 cows), received 10 μg of BA (i.m.) at the artificial insemination time (d 0), T3 - (5 heifers and 16 cows), received 10 μg of BA (i.m.) 13 days after A.I. (d 0) and, T4 (=T2 + T3) (5 heifers and 15 cows), received 10 μg of AB (i.m.) on days 0 and 13 da AI. The injection of SF and BA were performed after blood collection. The animals were housed in free-stall with visual heat detection three times a day, each for 15 minutes. Heifers with body weight greater than 300 kg and cows considered able for reproduction, 45 days postpartum, were inseminated at the end of estrus by just one technician, with a semen pool from three differents sires, of proved fertility. Heifers were fed with grounded Pennisetum sp., hay grass, corn silage, orange peel and multiples mixtures and cows with total ration mixture (TMR) with variable quality according to the production. The serum urea concentration, total cholesterol and the plasma progesterone level (P4), and estimated the body condition score (ECC), days open (DPP), index of temperature and humidity (THI), minimum temperature (TMin) e maximum (TMax). The buserelin acetate (AB) did not affected the pregnancy rate of heifers or cows showing values of 100.00 and 37.52 (T1); 20.00 and 33.34 (T2); 100.00 and 31.25 (T3); and 40.00 and 40.00% (T4), respectively. In the heifers the injection of buserelin acetate at the IA time (T2) increased the cholesterol and decreased the P4 concentration when compared to the control heifers, and decreased the cholesterol and P4 concentration in the cows from T2, T3 and T4. The injection of buserelin to heifers and cows on the 13th (T3 and T4) reduced the urea concentration.
O experimento foi conduzido na Agropecuária Paraíso, localizada no município de Santa Teresa, ES, para estudar o efeito do acetato de buserelina (AB), análogo de GnRH, sobre a fertilidade de novilhas e vacas lactantes. Oitenta e dois animais, 20 novilhas e 62 vacas, ½ Holandês/Zebu a Holandês puro de origem (P.O.), foram alocados em um delineamento experimental inteiramente casualizado, em quatro tratamentos, como a seguir: T1 - tratamento controle (5 novilhas e 16 vacas), aplicaram-se 2,5 mL de soro fisiológico (SF), intramuscular (i.m.), no momento da Inseminação Artificial (I.A.) (d 0); T2 - (5 novilhas e 15 vacas), aplicaram- se 10 μg de AB (i.m.) no dia da I.A. (d 0), T3 - (5 novilhas e 16 vacas), com aplicação de 10 μg de AB (i.m.) no 13o dia após a I.A. (d 0); e T4 (= T2 + T3) - (5 novilhas e 15 vacas), com aplicação de 10 μg de AB (i.m.) nos dias 0 e 13 da I.A. (d 0). As aplicações de SF e AB foram feitas após a coleta de sangue para dosagem hormonal e de metabólitos. Os animais foram alojados em free-stall , com observação de estro três vezes ao dia. As novilhas acima de 300 kg de peso vivo e as vacas consideradas aptas à reprodução, a partir de 45 dias no pós-parto, foram inseminadas ao término do estro, por um único técnico, com sêmen da mesma partida de três touros de comprovada fertilidade. As novilhas foram alimentadas com capim-elefante picado, feno de gramíneas, silagem de milho, bagaço de laranja peletizado e mistura múltipla e as vacas, com ração total misturada (TMR) de composição variável de acordo com a produção. Foram dosadas as concentrações séricas de uréia, colesterol total e progesterona (P4) plasmática e determinados o escore de condição corporal (ECC), dias no pós-parto (DPP), índice de temperatura e umidade (THI) e temperaturas mínima (TMín) e máxima (TMáx). O acetato de buserelina (AB) não afetou a taxa de gestação em novilhas e vacas apresentando valores de 100,00 e 37,52 (T1); 20,00 e 33,34 (T2); 100,00 e 31,25 (T3); e 40,00 e 40,00% (T4), respectivamente. Nas novilhas a administração do acetato de buserelina no momento da IA (T2) aumentou a concentração de colesterol e diminuiu a de P4 em relação ao controle e, nas vacas (T2, T3 e T4) diminuiu a concentração de colesterol e de P4. A administração de acetato de buserelina nas novilhas e nas vacas no 13º dia (T3 e T4) reduziu a concentração de uréia.