Effect of phorbol ester on cAMP-dependent protein kinase activity in cardiomyocytes.
Cardiomyocytes isolated from neonatal rats were treated with phorbol-12-myristate-13-acetate (PMA) ranging from 10(-11) to 10(-7) mol/L for 20 min, causing cytosol protein kinase A (PKA) activity to decrease while particulate PKA activity increase in a concentration-dependent manner. The change of PKA activity induced by PMA was abolished completely by pretreatment of polymyxin B or depletion of protein kinase C (PKC). Type II PKA activity in particulate fraction was enhanced remarkably, while that of type I PKA was not altered when the cells were treated with 100 nmol/L PMA. The results suggested that subcellular distribution and activity of PKA in cardiomyocytes may be regulated by PKC.
Zhou
W
W
Department of Pathophysiology, Institute of Basic Medical Science, Beijing.
Xiao
D
D
Zheng
C
C
Wang
X
X
Zhang
J
J
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology*; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism*; D009206:Myocardium / Q000166:cytology / Q000201:enzymology*; D011112:Polymyxin B / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D000242:Cyclic AMP; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D011112:Polymyxin B; D013755:Tetradecanoylphorbol Acetate