Proportion Of Large Follicles Research Articles

Impact Of Hypotensive Action Of Angiotensin Converting Enzyme Inhibitor On Ovarian-Intraovarian Blood Flow And Follicles Development In Goats Hormonally Stimulated With Repeated Fsh-Ecg Treatment

Background: Recent evidence shows that the renin-angiotensin system (RAS) participates in important reproductive processes, such as steroidogenesis, folliculogenesis, oocyte maturation and ovulation. Several studies have proposed to use an angiotensin-converting enzyme (ACE) as a RAS modulator, aiming to improve reproductive efficiency, however, the presence of the main components of this system in reproductive tissues still need to be further investigated, since the physiological functions seem to be species-specific. The aim of this study was to assess the impact of enalapril-maleate, an ACE inhibitor, during repeated gonadotropins treatment on ovarian blood flow and follicular development in goats. Materials, Methods and Results: Twenty Anglo-Nubian cross-bred goats were equally grouped according to parity (n=10/group): nulliparous and multiparous parity. In each group, five animals were randomly selected to receive 0.4 mg.kg-1 of enalapril-maleate during 11 days of estrus synchronization and gonadotropins treatments. The other animals received the same volume of saline solution. Estrus synchronization of all goats was made by intramuscular administration of PGF2α analog, followed 48 h later by intravaginal insertion of a controlled internal drug release device. Forty-eight hours after device withdrawal, a single dose of 60 mg of FSH plus 300 UI of eCG was administered and repeated every 4 days to complete 3 treatments. Transrectal ultrasonography was performed using pulsed and color Doppler to evaluate Doppler velocimetrics parameters of the ovarian artery and intraovarian blood flow, respectively, and B-mode real-time ultrasound scanner to evaluate the follicular development. In the females treated with enalapril-maleate was observed a significant reduction of systolic and diastolic peak, without difference according to parity. In addition, in the third session of hormonal stimulation, only the groups (nulliparous and multiparous) not treated with enalapril maleate had a significant increase in the intraovarian blood flow (Doppler area). In treated group was also found a greater number of small follicles, a lower proportion of follicle ≥ 5 mm and a smaller follicular size. In the same group, the nulliparous females had a lower proportion of large follicles compared to the saline group, otherwise, there were no differences between the treatments in multiparous goats. In the group treated with enalapril maleate, higher number of large follicles was observed in multiparous animals than in the nulliparous ones.Discussion: In vivo and in vitro studies have shown clear effects of RAS modulation on reproductive aspects. Our results confirmed the hypotensive effect of enalapril maleate on the ovarian artery and intraovarian blood flow, also showing that the administration of the drug reduced the process of follicular depletion and the growth of large follicles. These findings suggest that the hypotensive effects observed in our experiment, result from the treatment with the ACE inhibitor, and that this alteration in hemodynamic parameters may be the main responsible for the lower follicular response observed in animals treated with enalapril-maleate. We suggest that further studies are necessary to elucidate possible effects of the administration of an ACE inhibitor on ovarian activity, especially in the expression of genes associated with follicular, oocyte and embryonic development. Finally, the study conclude that the administration of enalapril-maleate in our experimental condition exhibit a hypotensive effect on ovarian circulatory system but did not show to promote a real benefit of follicular development in goats.

Efeito do tempo da aplicação de prostaglandina na resposta folicular em ovelhas durante o ciclo estral

Avaliou-se a resposta ovariana, usando ultrassonografia transretal, à aplicação de duas injeções de prostaglandina (PGF2α) em diferentes intervalos. Foram utilizadas 14 fêmeas ovinas da raça Bergamácia durante a estação reprodutiva, sendo que todas receberam uma dose intramuscular de um análogo de PGF2α. As ovelhas foram distribuídas em dois grupos (n = 7). Em um dos grupos, a PGF2α foi administrada sete dias (PG7) e, no outro, nove dias (PG9) depois da ovulação, quando o folículo dominante da onda 2 encontrava-se nas fases de crescimento e platô, respectivamente. Examinaram-se os ovários diariamente, utilizando-se um ultrassom Aloka 500, provido de um transdutor linear transretal de 7,5 MHz. A ultrassonografia foi iniciada um dia antes da segunda aplicação de prostaglandina até o dia 10 depois da ovulação em ambos os grupos. Amostras de sangue foram colhidas, via punção jugular, a cada dia, para quantificação de progesterona. As concentrações plasmáticas de progesterona mostraram-se menores no PG7 quando comparado com o PG9, imediatamente antes do tratamento com a PGF2α (4,10 ± 0,17 vs 4,91 ± 0,29 ng/mL; respectivamente). A média do diâmetro máximo atingido pelo folículo dominante da onda 2 foi maior no grupo tratado PG7 comparado com o PG9 (5,5 ± 0,19 vs 4,29 ± 0,26 mm). Houve efeito do dia nos folículos totais. A quantidade de folículos pequenos (2-2,5 mm) foi maior (4,57 ± 0,78 versus 8,42 ± 1,36) no dia 6, nos grupos PG7 e PG9, respectivamente, mas não foram observadas mudanças nos folículos médios (3-3,5 mm) entre os grupos tratados. A proporção de folículos grandes (4 mm) aumentou depois da luteólise; os valores foram menores nas ovelhas tratadas no PG7 e mantiveram-se estáveis no tempo no PG9. Em ovelhas com rápida e completa luteólise, a ovulação ocorre no folículo dominante da onda 2 em fêmeas tratadas sete ou nove dias após a ovulação.

Effect of Removal of Follicles through Repeated Transvaginal Follicle Aspiration on Subsequent Follicular Populations in Murrah Buffalo (Bubalus bubalis)

This study was conducted to investigate the effects of removal of all ovarian follicles through repeated transvaginal follicle aspiration (TVFA) on the subsequent follicular populations in buffaloes. This information is crucial for determining the optimum time interval between successive aspirations for recovering oocytes from live buffaloes through Transvaginal Oocyte Retrieval (TVOR). The oestrus of cycling buffaloes (n=5) were synchronized by a single PGF injection schedule. All the ovarian follicles were removed once every 7 days for 6 weeks through TVFA, starting from Day 7 of the oestrous cycle (Day 0 = day of oestrus). The number and size of individual ovarian follicles was recorded at Day 3 and Day 5 (Day 0 = day of TVFA) through transrectal ultrasonography. The follicles were classified on the basis of their diameter as small (3-5 mm), medium (6-9 mm) and large (≥10 mm). There was no difference in the number of small and medium follicles, and the number of total follicles between Day 3 and Day 5. However, the number of large follicles was significantly higher (p<0.05) at Day 5 than that at Day 3. There was a significant (p<0.05) decrease in the proportion of small follicles and an increase (p<0.05) in the proportion of large follicles from Day 3 to Day 5, with no change in the proportion of medium follicles. The number of total follicles at Day 3 or Day 5 did not differ during the 6 TVFA sessions. It can be concluded that an interval of 3 days is more suitable than that of 5 days between successive aspirations for recovering oocytes through TVOR in a twice weekly schedule and that repeated removal of follicles through TVFA does not adversely affect the number of total follicles 3 or 5 days after TVFA. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 5 : 632-636)

Longitudinal assessment of ovarian perifollicular and endometrial vascularity by power Doppler ultrasound in pregnant and non-pregnant cycles in the IVF setting.

This longitudinal study aimed to compare ovarian perifollicular and endometrial blood flow (PFBF and EBF, respectively) during the follicular phase in pregnant and non-pregnant IVF cycles. Serial transvaginal scans were performed in 15 subjects undergoing IVF treatment. Both PFBF and EBF were subjectively graded (grades 0-4 for PFBF and grades 1-3 for EBF). After confirmation of clinical pregnancy, the treatment cycles were grouped into 'Pregnant' and 'Non-pregnant' cycles. Ovarian PFBF and EBF were retrospectively compared between the two groups. In pregnant cycles, the proportion of large (> or = 15 mm) follicles with high (24) grade PFBF increased with time throughout the follicular phase, and the proportion of large follicles with poor (0-1) grade PFBF decreased. In non-pregnant cycles these trends were reversed. There was no difference in EBF between the two groups. The pattern of ovarian PFBF but not EBF may be predictive of treatment outcome.

Effect of intrauterine devices on pituitary gonadotropins, ovulation and pseudopregnancy in rabbits.

An experiment was planned to test the effects of IUD in rabbits who had a pseudopregnancy before the treatment. The effects of IUD were compared in animals having a treatment period of 4 days of estrus versus a long treatment of a pseudopregnancy plus 8 days of estrus. 80 rabbits in the first 24 hours of estrus following a pseudopregnancy were assigned to 8 groups of 10 each. The experiment was 2 by 2 by 2 factorial the factors being: 1) treatment with IUD in both the uterine horns; 2) duration of treatment; and 3) mating. The treatment with IUD caused a significant increase in variability of the length of pseudopregnancy. In the treated animals the proportion of large follicles that had ovulated by 11 hours after mating was significantly less than in the control groups. This effect was more pronounced when the IUD had its effect for a shorter period than for a longer period. There was no significant difference in the total number of follicles that had matured in the different groups. The relative potency of the pituitary gland was higher in the non-mated than in the mated animals but differences due to the IUD treatment were not significant either. The lesser proportion of follicles ovulating by 11 hours in the treated animals is suggestive of an interference with acute release of luteinizing hormone (LH). The less pronounced effects of the IUDs after they had been installed for the longer time appear to reflect some kind of adaptation in their presence.