Bovine granulosa cell culture for assessment of potency and specificity of antibodies to pregnant mares' serum gonadotrophin.

ABSTRACT

Antibodies to pregnant mares' serum gonadotrophin (PMSG) neutralize the effect of PMSG in vivo and increase the number of transferable embryos 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 granulosa cells in a serum-free culture system as a bioassay for antibodies to PMSG. Granulosa cells (2-3 x 10(5) viable cells) were cultured with varying doses of PMSG and/or an anti-PMSG for 4 days. Whilst progesterone production (ng/micrograms 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 follicle-stimulating hormone or LH on progesterone production of bovine granulosa cells in vitro. The bovine granulosa cell culture system is a potential in vitro bioassay method for testing the specificity and the neutralizing capacity of different anti-PMSG preparations.