A pertussis/cholera toxin sensitive G-protein may mediate vasopressin-induced inositol phosphate formation in smooth muscle cell.
Arg-vasopressin (AVP) stimulates the production of inositol-1,4,5-triphosphate, inositol-1,4-bisphosphate and inositol-1-phosphate in A10 smooth muscle cell line. The AVP stimulation is rapid, time and dose dependent with an ED50 value of 5 nM. Protein kinase C activator, phorbol ester blocks the AVP effect on the production of inositol phosphates, suggesting that AVP induced phospholipase C (PLC) activation is under the negative feedback regulation by diacylglycerol production. Prolonged overnight treatment with either pertussis toxin and cholera toxin resulted partial inhibition of AVP-induced production of inositol phosphates. This result suggests that a novel G-protein similar to transducin might be involved in the AVP-induced PLC activation.
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002772:Cholera Toxin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007295:Inositol Phosphates / Q000096:biosynthesis*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D037342:Pertussis Toxin; D051381:Rats; D013403:Sugar Phosphates / Q000096:biosynthesis*; D010738:Type C Phospholipases / Q000378:metabolism; D014667:Vasopressins / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D007295:Inositol Phosphates; D013403:Sugar Phosphates; D010566:Virulence Factors, Bordetella; D014667:Vasopressins; D001127:Arginine Vasopressin; D002772:Cholera Toxin; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D002118:Calcium