Respuesta ovárica en cobayas (Cavia porcellus) a un protocolo de superovulación con diferentes dosis de gonadotropina coriónica equina

Abstract

Ovarian response was evaluated in guinea pigs (Cavia porcellus) presynchronized for 15 days with progesterone prior to the superovulation protocol with different doses of equine chorionic gonadotropin (eCG): 100 IU and 150 IU, applied 24 hours before and at the time (0 hours) of progesterone suppression. Twenty-six multiparous guinea pigs, 100 ± 5 days old, weighing between 800 to 1150 grams were randomly assigned to 5 groups: 100 IU A, 150 IU A, 100 IU D, 150 IU D and control. The number, type and quality of structures were not affected by administering eCG, but it did induce changes on ovarian characteristics; the groups treated with eCG presented greater ovarian volume (100 IU A 77.3±22.9; 150 IU A 52.2±19; 100 IU D 88.2±60.4; 150 IU D 71.1±44.4 mm3 vs. control 21.7± 5.28 mm3), higher number of follicles (100 IU A 10±8; 100 IU D 10.4±9; 150 IU D 15.8±7.2) and larger follicular diameter (100 IU A 0.8±0.5; 150 IU A 1.2±0.7; 100 IU D 0.5±0.3; 150 IU D 0.4±0.2). Whereas, the diameter of the corpora lutea of 150 IU A and 150 IU D was smaller (150 IU A 0.4±0.4 and 150 IU D 0.4±0.4 vs 100 IU A 0.7±0.2 and 100 IU D 0.9±0.1). Also, application of eCG promotes follicular luteinization. In conclusion, administering eCG before or on the day of progesterone suppression does not affect the number, type and quality of recovered structures, but it does have an effect on the morphological characteristics of the ovary.