Efecto de la aplicación de un tratamiento a base de hormona gonadotropina menopáusica humana (hMG) en diferentes tiempos sobre la respuesta ovárica de cobayas sincronizadas

Abstract

The objective of the study was to evaluate the effect of human menopausal gonadotropin hormone (hMG) applied at different times on the superovulatory response of guinea pigs with prior synchronization of the estrous cycle. A total of 21 females with a mean age of 100 ± 5 days, weighing between 800 and 1150 g, and which had a feeding adaptation period of 15 days, were selected. Three groups were formed, which were synchronized by administering oral P4 (Altrenogest®, 0.22mg/kg) for 15 days; the first group (A-hMG) was administered a dose of 5 IU/kg/day of hMG on days 13, 14 and 15 of synchronization; the second group (D-hMG) was administered 5 IU/kg/day of hMG on day 15 of synchronization, 16 and 17 post-synchronization; the third group was considered the control group. The administration of hMG significantly increased (p<0.05) the number of corpora lutea in the D-hMG group 17.1 ± 5.4 compared to the A-hMG group 4.5 ± 0.6 and control 3, 0 ± 0.7, in addition to the total number of structures recovered. There were no significant variations in the opening of the vaginal membrane (p<0.05); taking as reference the moment of application and withdrawal of the progestin; as well as the other morphometric variables: ovarian volume, size of corpora lutea and follicles, did not differ significantly. The results suggest that the application of hMG caused a positive effect on the ovarian response, an increase in the number of recovered structures and embryos; this is explained by the presence of a greater number of recovered corpora lutea and embryos.