Peripheral sympathetic denervation provoked by guanethidine injection results in the advancement of ovulation, induced by sequential gonadotrophin treatment, in prepubertal female guinea pigs
Por:
Riboni L., Châvez E., Dommguez R.
Publicada:
1 ene 1997
Resumen:
There is evidence that the sympathetic innervation of the ovary plays a role in regulating ovulation. We analysed the possibility that the ovarian sympathetic innervation modulates the effects of gonadotrophins on ovulatory ability in the prepubertal guinea pig. Injection of guanethidine sulfate into newborn female guinea pigs resulted in the advancement of the age of vaginal opening, as compared with untouched control animals (27 ± 9 vs 37 ± 0.9 days, p < 0.05). 24-48 h after the vaginal opening, neither untouched control nor guanethidine treated animals showed signs of ovulation (presence of fresh corpora lutea in the ovaries). The sequential injection of 10 IU of pregnant mare's serum gonadotrophin (PMSG), followed 56 h later by 10 IU of human chorionic gonadotrophin (hCG) into 10 day-old guinea pigs resulted in the advancement of the age of vaginal opening (22 ± 2.3 days vs 37 ± 0.9 days, p < 0.05). When PMSG-hCG was administered to guanethidine-treated animals, the age of vaginal opening was significantly advanced as compared with PMSG-hCG-treated animals (17 ± 0.8 vs 22 ± 2.3 days, p < 0.05). Almost all animals treated with PMSG-hCG, denervated or not,had fresh corpora in their ovaries. Differences in the number of fresh corpora lutea between denervated and non-denervated guinea pigs treated with PMSG-hCG were not observed. These results indicate that the sensitivity of the follicles to gonadotrophins is modulated in an inhibitory way by noradrenergic innervation.
Filiaciones:
Riboni L.:
Departamento de Biologia de la Reproduction, Benemérita Universidad Autônoma de Puebla, Puebla, Mexico
Châvez E.:
Departamento de Biologia de la Reproduction, Benemérita Universidad Autônoma de Puebla, Puebla, Mexico
Dommguez R.:
Biology of Reproduction Research Unit, Facultad de Estudios Superiores Zaragoza, Universidad National Autônoma de Mexico, Mexico
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