Metabolism of 4,7,10,13,16-docosapentaenoic acid by human platelet cyclooxygenase and lipoxygenase.
Washed human platelets are shown to metabolize 4,7,10,13,16-docosapentaenoic acid into three major metabolites which were purified by reverse-phase HPLC. The mass spectra of the methyl ester-trimethylsilyl ether and ethyl ester-trimethylsilyl ether of compound A established it as delta 4-dihomo-thromboxane B2. Compound B was shown to be 14-hydroxy-4,7,10,12-nonadecatetraenoic acid, which is analogous to 12-hydroxy-5,8,10-heptadecatrienoic acid from arachidonic acid. Compound C was produced via an indomethacin-insensitive pathway and was identified as 14-hydroxy-4,7,10,12,16-docosapentaenoic acid. Time- and substrate-dependent studies showed that compounds A,B and C were produced approximately 10,15 and 65% of the extent to which thromboxane B2, 12-hydroxy-5,8,10-heptadecatrienoic acid and 12-hydroxy-5,8,10,14-eicosatetraenoic acid were produced, respectively, from arachidonic acid.
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood; D001792:Blood Platelets / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D006801:Humans; D008084:Lipoxygenase / Q000097:blood*; D013058:Mass Spectrometry; D011451:Prostaglandin-Endoperoxide Synthases / Q000097:blood*; D013997:Time Factors
D001095:Arachidonic Acids; D005231:Fatty Acids, Unsaturated; D016718:Arachidonic Acid; D008084:Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; C026219:docosapentaenoic acid