Effect of passive immunization with buffalo follicular fluid antisera on ovarian activity in guinea pigs

Ovarian activity and follicular populations were studied in guinea pigs (Cavia porcellus) following administration of antisera against buffalo follicular fluid (buFF). Antibodies were raised in rabbits and the titre tested by immunodiffusion assay. Fourteen guinea pigs cycling normally were randomized into two groups. Animals in Group I (n = 8) were treated (i.p.) with 0.5 ml antisera and in Group II (control, n = 6) with the same volume of normal rabbit serum at 12 h intervals on the 10th and 11th day of their oestrous cycle. They were sacrificed 24 h after onset of estrus when ovulation points were counted and ovaries processed for microscopical examination. Treatment with buFF-antisera increased ovulation rate (3.6 vs. 2.0; p < 0.01) but had no significant effect on the total number of follicles. However, the treatment reduced the percentages of atretic follicles in all size classes. These results indicated that the administration of a buFF-antisera produced in the rabbits increased ovulation rate in guinea pigs by reducing the incidence of atresia.