Proteoglycan production by bovine granulosa cells in vitro occurs in response to fsh

Bovine granulosa cells from small (1-9 mm) or large (10-20 mm) follicles were incubated in a chemically defined medium containing 5 muCi/ml [3H]glucosamine, gonadotropins or polypeptide hormones, 8-Br-cAMP, theophylline or trifluoperazine (TFP). Radiolabeled proteoglycans were precipitated with 10% phosphotungstic acid. Maximum incorporation of isotope occurred in 45-60 min. Radiolabeled products were completely hydrolyzed with chondroitinase ABC. FSH, but not LH or hCG, yielded a significant log-dose response. High doses of hCG inhibited the ability of granulosa to respond to FSH. No other hormone altered the FSH dose-response curve. Addition of 8-Br-cAMP or theophylline mimicked the FSH response. The FSH effect was blocked by TFP, an inhibitor of calmodulin, but cAMP or theophylline overcame the effect of TEP. No distinct difference in response to these various compounds was noted between granulosa from small or large follicles. This system provides a biochemical marker for evaluating a mechanism of action for FSH.