Relationship between superovulation and embryo production with ovarian follicular population before superovulatory treatment in Brazilian Bergamasca sheep / [Relação da resposta superovulatória e produção embrionária com a população folicular ovariana antes do tratamento superovulatório de ovelhas da raça Bergamácia Brasileira]

The objective of this study was to quantify the superovulatory response and embryo production of Brazilian Bergamasca sheep and to evaluate the link to the follicular condition before superovulatory treatment, as a reference for selection of donors with potential for superovulation. Follicular population of twenty-three sheep was evaluated by ultrasound during metestrus phase of the estrous cycle and divided into groups of low, medium and high follicular population. Subsequently, they were synchronized, superovulated with 133mg of pFSH, mated and subjected to embryo collection. The superovulatory response (9.0±3.3 vs 10.7±6.2 vs 13.8±7.1) and embryo production (4.0±3.8 vs 2.6±2.0 vs 1,8±4.0) were similar between groups (P>0.05). There was a positive correlation between the number of follicles during the metestrus phase and the number of corpus luteum with premature regression (PLR) (0.52) and a negative correlation between the recovery rate and PLR (-0.44) (P<0.05). The sheep that presented PLR had more follicles during metestrus (16.9±7.8 vs 12.7±3.2) and lower embryo recovery rate (38.8±29.3 vs 72.2±29.9) than those with functional CLs (P<0.05). Follicular quantification during metestrus phases was unable to identify donors with high embryo production. Animals with PLR had a larger follicular population during metestrus and lower embryo recovery rate.(AU)

O objetivo deste trabalho foi quantificar a resposta superovulatória e a produção embrionária de ovelhas Bergamácia Brasileira e relacioná-las com a condição folicular antes do tratamento superovulatório, como referência para seleção de doadoras com potencial para superovulação. Vinte e três ovelhas foram avaliadas quanto à população folicular por ultrassonografia na fase de metaestro do ciclo estral e divididas em grupos com baixa, média e alta população folicular. Posteriormente foram sincronizadas, superovuladas com 133mg de pFSH, acasaladas e submetidas à coleta de embriões. A resposta superovulatória (9,0±3,3 vs. 10,7±6,2 vs. 13,8±7,1) e a produção embrionária (4,0±3,8 vs. 2,6±2,0 vs. 1,8±4,0) foram semelhantes entre os grupos (P>0,05). Houve correlação positiva entre o número de folículos no metaestro e o número de corpos lúteos com regressão prematura (RPCL) (0,52) e correlação negativa entre a taxa de recuperação e RPCL (-0,44) (P <0,05). As ovelhas que apresentaram RPCL tiveram mais folículos no metaestro (16,9±7,8 vs. 12,7±3,2) e menor taxa de recuperação embrionária (38,8±29,3 vs. 72,2±29,9) do que as que apresentaram CLs funcionais (P<0,05). A quantificação folicular nas fases de metaestro não foi capaz de identificar doadoras com alto potencial de produção embrionária. Animais com RPCL tiveram maior população folicular no metaestro e menor recuperação de embriões.(AU)

Effects of echinomycin on endothelin-2 expression and ovulation in immature rats primed with gonadotropins

Echinomycin is a small-molecule inhibitor of hypoxia-inducible factor-1 DNA-binding activity, which plays a crucial role in ovarian ovulation in mammalians. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1alpha-mediated endothelin (ET)-2 expressions contributed to ovarian ovulation in response to human chorionic gonadotropin (hCG) during gonadotropin-induced superuvulation. By real-time RT-PCR analysis, ET-2 mRNA level was found to significantly decrease in the ovaries after echinomycin treatment, while HIF-1alpha mRNA and protein expression was not obviously changed. Further analysis also showed that these changes of ET-2 mRNA were consistent with HIF-1 activity in the ovaires, which is similar with HIF-1alpha and ET-2 expression in the granulosa cells with gonadotropin and echinomycin treatments. The results of HIF-1alpha and ET-2 expression in the granulosa cells transfected with cis-element oligodeoxynucleotide (dsODN) under gonadotropin treatment further indicated HIF-1alpha directly mediated the transcriptional activation of ET-2 during gonadotropin-induced superuvulation. Taken together, these results demonstrated that HIF-1alpha-mediated ET-2 transcriptional activation is one of the important mechanisms regulating gonadotropin-induced mammalian ovulatory precess in vivo.

[ ultrastructural effects of superovulatory drugs on mouse endometrial basement membrane]

The endometrial basement membrane has a major role in implantation of embryo. Studies have recently shown that the rate of successful implantation in stimulatory cycles is less than in normal cycle due to detrimental effect of superovulatory drugs on endometrium. To investigate the effect of stimulatory drugs on ultrastrucures of mouse endometrial basement membrane. The endometrial samples were obtained form 30 naturally pregnant mice [control group] and 30 syperovulated mice [experimental group] at the time of implantation [120 h after hCG injection]. Induced with PMSG [10 IU] and hCG [10 IU]. The specimens were processed for electron microscopic studies. Qualitative [based on electron density] and quantitative [thickness of basement membrane] studies were performed on micrographs. The data were analyzed using Mann-Whitney statistical test]. The qualitative observation of the case group revealed a well developed RER, increased number of mitochondria and high electron density of basement membrane. The quantitative data demonstrated that the thickness of basement membrane and lamina densa were significantly increased in the case group compared with control group [0.283 +/- 0.0777, 0.158 +/- 0.00827 vs. 0.239 +/- 0.0082, 0.155 +/- 0.0111, P< 0.05]. It can be concluded that superovulation drugs may lead to low implantation rate by changing the endometrial basement membrane

Response related enzymatic changes in ovaries of superovulated mice.

Adult female mice were superovulated with PMSG followed by HCG and 140 blastocysts and 69 morulae were recovered from 24 mice. On the basis of the response, mice were divided into six groups; non responders, 1-5, 6-10, 11-20, 21-30 and >30 embryos. The ovaries of the animals were pooled group wise, homogenized in PBS (pH 7.4) and after centrifugation for 10-15 minutes, the supernatant was analyzed for the enzymes, guanine oxaloacetate transaminase (GOT), guanine pymvate transaminase (GPT), acid phosphatases (ACP) and alkaline phosphatases (AKP). Acid and alkaline phosphatase activities did not show any variation in relation to response to superovulation but GOT and GPT showed significantly increased activity in response to induction of superovulation. A statistically significant positive correlation was found between GOT and GPT activities and the superovulatory response in mice.

Impact of PGF2 alpha administration on progesterone pattern during and after PMSG treatment in buffaloes

Thirteen buffalo-cows and 6 heifers were subjected for superovulatory treatment using 3000 iu PMSG [Gestyl], 25 mg PGF2-alpha [Lutalyse] were injected 48 hours after PMSG treatment and at day eight of the estrous cycle after superovulatory treatments. Ovarian and progesterone changes were studied in buffalo-cows and heifers during and after superovulatory treatments. 84.6% and 83.3% of buffalo-cows and heifers exhibited estrous within 2.46 +/- 0.78 and 2.4 +/- 1.14 days, respectively, following treatment with lutalyse. Whereas, the intervals averaged 3.27 +/- 1.05 and 3.4 +/- 1.14 days when treated at day 8 after superovulation in buffalo-cows and heifers, respectively. Plasma progesterone concentrations averaged 3.74 +/- 1.53 and 1.28 +/- 0.91 ng/ml before treatment with lutalyse in buffalo-cows and heifers, respectively, followed by significant decline 24 hours after treatment in both buffalo-cows and heifers [1.12 +/- 0.71 and 0.74 +/- 0.38 ng/ml, p <0.01] and reached the lowest concentration 72 hours after treatment [0.20 +/- 0.09 and 0.24 +/- 0.24 ng/ml, respectively]. A marked elevation in plasma progesterone concentration following superovulatory treatment in buffalo-cows [15.02 +/- 10.44 ng/ml] and heifers [17.87 +/- 10.72 ng/ml] was recorded

Superovulation and embryo recovery in rabbits (Oryctolagus cuniculus) using different doses of pregnant mare serum gonadotrophin (PMSG).

Present investigation was conducted to study the ovarian response and embryo recovery using different PMSG dose levels. Six rabbits each were assigned randomly to treatment 1 (PMSG 50 IU + hCG 100 IU), treatment 2 (PMSG 75 IU + hCG 100 IU) and the control group (no hormone administered). PMSG injection (im) was followed 68 hr later by natural mating to a fertile rabbit buck and human chorionic gonadotrophin (hCG) injection iv post coitum. Embryos were recovered 96 hr post coitum by a modified surgical method. Mean number of ovulations in the control group differed significantly from treatment 1 and 2, but no significant difference was observed between treatments 1 and 2. Mean embryo recovery percentage was lowest in treatment 2 and highest in the control group. The higher dose PMSG (treatment 2) was observed to be more disturbing in terms of recovery of embryos as well as their morphology.

Fertilización in vitro y transferencia de embriones: segunda fase / Fertilization in vitro and embryons transfer: second phase

Se practicó la técnica de FIV-TE en un total de 58 veces en 56 pacientes de la Unidad de Reproducción Humana de la Clínica "El Avila", con factor tuboperitoneal de esterilidad. Las pacientes fueron sometidas a superovulación con citrato de clomifeno y gonadotropina y el día esperado de ovulación se practicó la recuperación de oocitos por laparoscopia. Se recuperaron un total de 251 oocitos (4,3 por laparoscopia) y se transfirieron 145 embriones (3,3 por paciente). Hubo un total de 6 embarazos (10,3 por laparoscopia y 14,6% por transferencia), 4 pacientes abortaron (66%), una paciente tuvo por parto normal, una niña que peso 3.000 Kgrs y una paciente está en avanzado estado de gravidez con una anmiocentesis que reveló un varón normal