Ovarian Localization of Immunoglobulin G and Inhibin α-Subunit in Guinea Pigs after Passive Immunization against the Inhibin α-Subunit

Abstract

The experiment was conducted to elucidate ovarian localization of immunoglobulin G (Ig G) and inhibin α-subunit and follicular development in guinea pigs after passive immunization against the inhibin α-subunit. Estrus was synchronized in laboratory guinea pigs by implanting progesterone containing-tubes. After removal of the progesterone implants, the guinea pigs were injected i.v. with 1.0 ml inhibin antiserum or normal goat serum (NGS). The results showed that Ig G mainly entered the follicular fluid of antral follicles, indicating that possibly inhibin antibodies could be a local regulator affecting follicular development in guinea pigs. The results also showed that passive immunization against inhibin increased the number of follicles and plasma concentrations of estradiol before ovulation, but did not change the plasma concentrations of follicle-stimulating hormone (FSH) or the numbers of follicles stained with inhibin antiserum. The present study first reports that the distribution of Ig G after injections of inhibin antiserum and confirms our previous hypothesis that only dominant follicles could be stained for inhibin α-subunit. The results also imply that only one injection of inhibin antiserum could not increase the ovulation rate in guinea pigs.