BOVINE GRANULOSA-CELL CULTURE FOR ASSESSMENT OF POTENCY AND SPECIFICITY OF ANTIBODIES TO PREGNANT MARES SERUM GONADOTROPIN

Antibodies to pregnant mares' serum gonadotrophin (PMSG) neutralize th e effect of PMSG in vivo and increase the number of transferable embry os when administered at the optimum time relative to the preovulatory luteinizing hormone (LH) surge in PMSG-stimulated cows. The objective of the present study was to investigate the possible use of bovine gra nulosa cells in a serum free culture system as a bioassay for antibodi es to PMSG. Granulosa cells (2-3 x 10(5) viable cells) were cultured w ith varying doses of PMSG and/or an anti-PMSG for 4 days. Whilst proge sterone production (ng/mu g DNA) of granulosa cells was stimulated by PMSG (p < 0.01) in a dose-dependent manner, increasing amounts of anti -PMSG neutralized (p < 0.01) this stimulatory effect of either follicl e-stimulating hormone or LH on progesterone production of bovine granu losa cells in vitro. The bovine granulosa cell culture system is a pot ential in vitro bioassay method for testing the specificity and the ne utralizing capacity of different anti-PMSG preparations.