Abstract:
To determine whether nitric oxide (NO) generation mediates human chorionicgonadotrophin (hCG)-induced prostaglandin E (PGE) secretion byoocyte-cumulus complexes (OCC), the secretion of PGE by cultured rat OCCin the presence of NO donors and NO synthase (NOS) inhibitors wascharacterized. NO donors (sodium nitroprusside and 3-morpholino-sydnonimine-hydrochloride) increased PGE accumulation in OCC to values similar to thoseobtained in the presence of hCG. The three NOS inhibitors tested(N G -nitro-L-arginine methyl ester,N<emph type="7">G -monomethyl-L-arginine andaminoguanidine) prevented the hCG-induced PGE accumulation in cultured OCC.This effect appears to be specific since D-enantiomersN<emph type="7">G -nitro-D-arginine methyl esterand N<emph type="7">G -monomethyl-D-arginine hadno effect. The present results suggest that NO mediates the hCG-inducedaccumulation of PGE in rat OCC, a process which may occurin vivo in preovulatory follicles prior to ovulation.