Phorbol ester inhibition of vasopressin-induced calcium efflux from cultured rat aortic myocytes.
The effect of the protein kinase C activator TPA was investigated on AVP-induced 45Ca release from rat aortic myocytes. In the nanomolar range TPA, but not 4 beta-phorbol, reduced the brief 45Ca efflux produced by AVP in the presence or in the absence of extracellular calcium. The maximal effect of TPA was to abolish the response to a half maximally active concentration of AVP, and to reduce by 50% the maximal response to the hormone. These results suggest that protein kinase C activation can exert a negative control on the early AVP-induced calcium mobilization in vascular smooth muscle.
D000818:Animals; D001013:Aorta, Thoracic; D001127:Arginine Vasopressin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D005260:Female; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D010704:Phorbols / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D010704:Phorbols; D001127:Arginine Vasopressin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium