Stimulation of prostacyclin production by vitamin C in ram seminal vesicle microsomes: possible mode of action.
The enhancing effect of vitamin C on the conversion of arachidonic acid, endoperoxide G2 and endoperoxide H2 to 6-keto-PGF 1 alpha, the stable metabolite of prostacyclin, by ram seminal vesicle microsomes was further investigated. From the incubations of these substrates with 1-tryptophan, catalase, superoxide dismutase and 15-HPETE it became clear that vitamin C apparently acts mainly through neutralization of the oxidative species formed during the reduction of endoperoxide G2 to endoperoxide H2. Although it has also a more direct stimulating activity on the prostacyclin synthase, a possible interference with hydroperoxy derivatives of arachidonic acid cannot be completely ruled out.
D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology*; D002374:Catalase / Q000494:pharmacology; D011464:Epoprostenol / Q000096:biosynthesis* / Q000494:pharmacology; D066298:In Vitro Techniques; D015289:Leukotrienes; D008054:Lipid Peroxides / Q000494:pharmacology; D008297:Male; D008861:Microsomes / Q000378:metabolism*; D011450:Prostaglandin Endoperoxides, Synthetic / Q000378:metabolism; D044262:Prostaglandin H2; D011462:Prostaglandins G / Q000378:metabolism; D011463:Prostaglandins H / Q000378:metabolism; D012669:Seminal Vesicles / Q000378:metabolism*; D012756:Sheep; D013482:Superoxide Dismutase / Q000494:pharmacology; D014364:Tryptophan / Q000494:pharmacology
D001095:Arachidonic Acids; D015289:Leukotrienes; D008054:Lipid Peroxides; D011450:Prostaglandin Endoperoxides, Synthetic; D011462:Prostaglandins G; D011463:Prostaglandins H; D044262:Prostaglandin H2; C038291:prostaglandin G2; C025086:15-hydroperoxy-5,8,11,13-eicosatetraenoic acid; D014364:Tryptophan; D011464:Epoprostenol; D002374:Catalase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid