Long-term phorbol ester treatment dissociates phospholipase D activation from phosphoinositide hydrolysis and prostacyclin synthesis in endothelial cells stimulated with bradykinin.
Bovine pulmonary artery endothelial cells (BPAEC) were prelabeled with [3H]choline or [3H]myristic acid to selectively label endogenous phosphatidylcholine. BPAEC were stimulated with ATP and bradykinin (BK), and phospholipase D (PLD) activation was detected as a 4-fold increase in [3H]choline in cells prelabeled with [3H]choline or as a 2- to 3-fold increase in [3H]phosphatidylethanol in cells prelabeled with [3H]myristic acid and stimulated in the presence of ethanol. Pretreatment of BPAEC with 0.1 microM phorbol 12-myristate 13-acetate (PMA) for 22 hr completely inhibited agonist-induced PLD activation, whereas prostacyclin synthesis and [3H]phosphoinositide ([3H]PIns) hydrolysis were enhanced in pretreated cells. Long-term PMA treatment thus dissociates agonist-induced PLD activation from [3H]PIns hydrolysis, and agonist-induced prostacyclin synthesis is not dependent upon PLD activation.
Martin
T W
TW
Department of Pathology, St. Louis University School of Medicine, Missouri 63104.
Feldman
D R
DR
Goldstein
K E
KE
Wagner
J R
JR
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis*; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002417:Cattle; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D006868:Hydrolysis; D007294:Inositol / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D007700:Kinetics; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D010703:Phorbol Esters / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism*; D010740:Phospholipases / Q000378:metabolism*; D011651:Pulmonary Artery; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D007295:Inositol Phosphates; D009227:Myristic Acids; D010703:Phorbol Esters; D010716:Phosphatidylinositols; D019814:Myristic Acid; D007294:Inositol; D015121:6-Ketoprostaglandin F1 alpha; D010740:Phospholipases; D010739:Phospholipase D; D013755:Tetradecanoylphorbol Acetate; D001920:Bradykinin