Impairment of follicular development by intra-ovarian infusion of gonadotrophin-releasing hormone antiserum in prepubertal pigs.

Antiserum against gonadotrophin-releasing hormone (GnRH) was infused into one ovary in 4 prepubertal gilts and control porcine serum was infused into one ovary in 4 other gilts. Ovaries were infused for 156 h, after which infused and non-infused ovaries were removed surgically and processed for histology. Infusion of GnRH antibodies did not alter (P greater than 0.10) concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) or oestradiol-17 beta, and GnRH titres in peripheral circulation were low, averaging 1:15. Weights of ovaries not infused were similar (P greater than 0.10) between treatment groups. There were fewer (P less than 0.05) follicles greater than 0.5 mm in diameter in the ovaries infused with GnRH antiserum than in the others, but there were no differences (P greater than 0.10) between treatment groups in the number of follicles less than 0.5 mm in diameter. Infusion of GnRH antibodies increased (P less than 0.05) the incidence of atresia in follicles with greater than 4 layers of granulosa cells compared with the other treatment groups. These results provide evidence that a peptide binding to the GnRH antibodies is involved directly in ovarian follicular development.