Inhibition of prostaglandin (PG) synthesis in sheep vesicular gland microsomes (SVGM) by nitroblue tetrazolium (NBT) and vitamin E (VE).
Previous studies have shown that NBT and VE together are potent inhibitors of platelet aggregation, secretion and PG synthesis. In this study, we evaluated the capacity of NBT to detect PG synthesis by SVGM. Aspirin pretreatment of SVGM decreased the amount of NBT reduced after addition of arachidonic acid, demonstrating that products generated by the cyclo-oxygenase were involved in NBT reduction. The influence of NBT and VE on PG synthesis by SVGM was then evaluated by measuring malondialdehyde (MDA) production. NBT or VE alone had no significant effect, but together these agents were as effective as aspirin in preventing MDA formation. The effect of NBT and VE on 14C-arachidonic acid conversion was followed by thin layer chromatography and radioscanning. Again, NBT or VE alone were ineffective, whereas the combination was as effective as aspirin in preventing conversion of arachidonic acid. We speculate NBT and VE together inhibit pg synthesis by scavenging a free radical species of arachidonic acid generated in the initial step of fatty acid peroxidation.
D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D009580:Nitroblue Tetrazolium / Q000494:pharmacology*; D010084:Oxidation-Reduction; D011448:Prostaglandin Antagonists / Q000494:pharmacology*; D011453:Prostaglandins / Q000096:biosynthesis*; D012669:Seminal Vesicles / Q000187:drug effects / Q000378:metabolism*; D012756:Sheep; D013778:Tetrazolium Salts / Q000494:pharmacology*; D014810:Vitamin E / Q000494:pharmacology*
D001095:Arachidonic Acids; D011448:Prostaglandin Antagonists; D011453:Prostaglandins; D013778:Tetrazolium Salts; D014810:Vitamin E; D009580:Nitroblue Tetrazolium; D008315:Malondialdehyde