Human chorionic gonadotropin activates the inositol 1,4,5-trisphosphate-Ca2+ intracellular signalling system in bovine luteal cells.
Human chorionic gonadotropin, hCG, a hormone which increases intracellular cAMP, provoked rapid (30 s) and sustained (up to 30 min) increases in the levels of inositol mono-, bis- and trisphosphates (IP, IP2 and IP3, respectively) in bovine luteal cells. LiCl (10 mM) enhanced inositol phosphate accumulation in response to hCG. Concentration-dependent increases in inositol phosphates, cAMP and progesterone accumulation were observed in hCG-treated luteal cells. hCG also induced rapid and concentration-dependent increases in cytosolic free Ca2+ as measured by quin 2 fluorescence. These findings demonstrate that hCG stimulates the phospholipase C-IP3 and diacylglycerol 'second messenger' system in the bovine corpus luteum.
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002417:Cattle; D002478:Cells, Cultured; D002712:Chlorides / Q000494:pharmacology; D006063:Chorionic Gonadotropin / Q000502:physiology*; D003338:Corpus Luteum / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000502:physiology*; D008094:Lithium / Q000494:pharmacology; D018021:Lithium Chloride; D013403:Sugar Phosphates / Q000502:physiology*
D002712:Chlorides; D006063:Chorionic Gonadotropin; D007295:Inositol Phosphates; D013403:Sugar Phosphates; D008094:Lithium; D000242:Cyclic AMP; D018021:Lithium Chloride; D002118:Calcium