calcimycin and mead-acid

5,8,11-Eicosatrienoic acid (20:3 omega 9), a fatty acid increased in the platelet phospholipids of man and animals fed saturated fats, was either added to human platelets simultaneously with the aggregating agents, or incorporated into the platelet phospholipids by preincubation. 20:3 omega 9 markedly increased the response of platelets to all aggregating agents tested when added simultaneously with the agent, but solely to thrombin and ionophore, after incorporation into the platelet phospholipids. The potentiating effects of 20:3 omega 9 on thrombin aggregation do not appear to be related to prostaglandin formation, but rather to the production of a monohydroxy derivative through the lipoxygenase pathway.

Topics: 8,11,14-Eicosatrienoic Acid; Aspirin; Calcimycin; Drug Synergism; Ethanol; Fatty Acids, Unsaturated; Humans; Platelet Aggregation; Thrombin

Rat basophilic leukemia (RBL-1) cells incubated with ionophore A23187 and 5,8,11-eicosatrienoic acid produced three slow-reacting substances identified as leukotrienes C3, D3 and E3 by spectroscopic, chromatographic and enzymatic methods. 5,8,11,14,17-Eicosapentaenoic acid was similarly converted by RBL-1 cells to leukotrienes C5, D5. and E5. Leukotrienes C4, D4 and E4 were also formed in these experiments from endogenous arachidonic acid. Time-course studies, incubations with 3H-labeled leukotriene C3 and effects of acivicin [L-(alpha S, 5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid; a gamma-glutamyl transpeptidase inhibitor] indicated that leukotrienes C and D are intermediates in the formation of leukotrienes E. L-Cysteine enhanced the conversion of leukotriene C3 to leukotriene D3 and inhibited further degradation of leukotriene D3 to leukotriene E3.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Arachidonic Acid; Arachidonic Acids; Basophils; Calcimycin; Chromatography, High Pressure Liquid; Cysteine; Glycine; Isoxazoles; Leukemia, Experimental; Leukotriene E4; Rats; SRS-A