Protein kinase C does not regulate diacylglycerol metabolism in aortic smooth muscle cells.
The effect of a reduction in protein kinase C activity on the metabolism of exogenous [3H]diC8 by freshly isolated smooth muscle cells from rabbit aorta and cultured A10 smooth muscle cells was determined. The metabolism of [3H]diC8 by both smooth muscle cell preparations was predominantly by hydrolysis to yield monoC8 and glycerol (lipase pathway); very little radioactivity was incorporated into phospholipids. Diacylglycerol lipase activity measured in vitro with A10 cell homogenates was much greater than diacylglycerol kinase activity. The addition of the protein kinase C inhibitor H-7 to incubations of isolated aortic smooth muscle cells and cultured A10 cells had no significant effect on the metabolism of [3H]diC8. Protein kinase C activity in cultured A10 cells preincubated for 20 h with a phorbol ester was reduced to 14% of control as a consequence of down-regulation, but diC8 metabolism was not changed. Therefore, protein kinase C does not regulate the metabolism of diacylglycerols in aortic smooth muscle cells.
Chuang
M
M
Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, Alberta, Canada.
Dell
K R
KR
Severson
D L
DL
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000201:enzymology*; D004075:Diglycerides / Q000378:metabolism*; D015536:Down-Regulation; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D007700:Kinetics; D008049:Lipase / Q000378:metabolism; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology*; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000502:physiology*; D011817:Rabbits; D014316:Tritium
D004075:Diglycerides; D007546:Isoquinolines; D010879:Piperazines; D014316:Tritium; C044295:1,2-dioctanoylglycerol; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D008049:Lipase