FORMATION OF 19(S)-HYDROXYEICOSATETRAENOIC, 19(R)-HYDROXYEICOSATETRAENOIC, AND 18(R)-HYDROXYEICOSATETRAENOIC ACIDS BY ALCOHOL-INDUCIBLE CYTOCHROME-P450 2E1

When reconstituted with cytochrome b5 and NADPH cytochrome P450 oxidor eductase, cytochrome P450 2E1 metabolized lauric, stearic, oleic, lino leic, linolenic, and arachidonic acid to multiple metabolites. Two maj or metabolites, accounting for 78% of the total metabolism, were produ ced with arachidonic acid. The V(max) for total metabolite formation f rom arachidonic acid was 5 nmol/min/nmol P450 with an apparent K(m) of 62 muM. Gas chromatography-mass spectrometry analysis identified the two major metabolites as mono-hydroxylated eicosatetraenoic acids (HET Es). The major HETE was 19-hydroxyeicosatetraenoic acid (19-HETE) and comprised 46% of the total metabolite produced. The second metabolite was the omega-2 hydroxylated metabolite (18-HETE) and comprised 32% of the total product formed. Chiral analysis demonstrated that 19-HETE w as 70% 19(S)-HETE and 30% 19(R)-HETE. In contrast, 18-HETE was essenti ally 100% R isomer. Approximately 18% of the total metabolite produced from arachidonic acid coeluted with epoxyeicosatrienoic acid (EET) st andards. The EET metabolites were 56.4% 14,15-EET and 43.6% as a mixtu re of 11,12-EET and 8,9-EET. 5,6-EET was not detected. Anti-P450 2E1 I gG inhibited arachidonic acid metabolism by renal and hepatic microsom es prepared from acetone-treated rabbits. With renal cortex microsomes , the formation of 18-HETE and 19-HETE was inhibited 67 and 25%, respe ctively, by the antibody. Liver microsomal formation of 18-HETE was in hibited by 87% and 19-HETE by 70%. Thus, under conditions where cytoch rome P450 2E1 is induced, the enzyme could contribute significantly to the formation of the omega-1 and omega-2 hydroxylated metabolites of arachidonic acid.