Identification of the molecular species of lysophosphatidic acid produced when platelets are stimulated by thrombin.
Platelets, when stirred with 3 U thrombin/10(9) platelets, produced significant quantities of palmitoyllysophosphatidic acid (2.17 ng/10(9) platelets), stearoyllysophosphatidic acid (2.11 ng/10(9) platelets), and arachidonoyllysophosphatidic acid (1.06 ng/10(9) platelets). When platelets were pretreated with 100 microM of the phospholipase A2 inhibitor U10029A, there was a significant decrease in thrombin-stimulated production of stearoyllysophosphatidic acid (to 0.16 ng/10(9) platelets), while arachidonoyllysophosphatidic acid production was unchanged. U10029A concomitantly increased thrombin-stimulated production of stearoyl-containing phosphatidic acid species (primarily stearoylarachidonoylphosphatidic acid) from 5.99 to 9.71 ng/10(9) platelets. The results are consistent with the concept that stearoyllysophosphatidic acid production in platelets occurs via phospholipase A2 degradation of phosphatidic acid.
Gerrard
J M
JM
Department of Pediatrics, University of Manitoba, Winnipeg, Canada.
Robinson
P
P
D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008246:Lysophospholipids / Q000097:blood*; D010741:Phospholipases A / Q000097:blood; D054467:Phospholipases A2; D011412:Propanolamines / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology*
D008246:Lysophospholipids; D011412:Propanolamines; C044751:U 10029A; D010741:Phospholipases A; D054467:Phospholipases A2; D013917:Thrombin