Enhancement of phospholipase A2 activation by phosphatidic acid endogenously formed through phospholipase D action in rat peritoneal mast cell.
Contribution of phosphatidic acid (PA) generated by activated phospholipase (PL) D to PLA2 activation was studied in rat peritoneal mast cells. Exogenous didecanoyl PA induced arachidonate liberation in the permeabilized cells which was inhibited by p-bromophenacyl bromide. Upon exposure of the cells to ethanol in a high enough concentration to prevent PA formation, A23187-induced arachidonate liberation was suppressed by 50% and the rest was completely inhibited by p-bromophenacyl bromide. In contrast, propranolol, which enhanced PA accumulation, significantly increased the arachidonate liberation. These results suggest that A23187-induced PLA2 activation may be potentiated, at least in part, by PA generated through PLD action.
Department of Biochemistry, Kyoto Pharmaceutical University, Japan.
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Sato
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Ishimoto
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Akiba
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Fujii
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D004789:Enzyme Activation; D007700:Kinetics; D008297:Male; D008407:Mast Cells / Q000201:enzymology*; D010537:Peritoneum / Q000166:cytology / Q000201:enzymology; D010712:Phosphatidic Acids / Q000378:metabolism / Q000502:physiology*; D010739:Phospholipase D / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D051381:Rats; D017208:Rats, Wistar
D010712:Phosphatidic Acids; D000001:Calcimycin; D010741:Phospholipases A; D054467:Phospholipases A2; D010739:Phospholipase D