Evidence that cytochrome P450 2E1 is involved in the (omega-1)-hydroxylation of lauric acid in rat liver microsomes.

The present study examined changes in hepatic CYP2E1 content and (omega-1)-hydroxylation of lauric acid in rats treated with pyridine, pyrazole, acetone, ethanol and 3-methylcholanthrene. The (omega-1)-hydroxylase activity was strongly correlated with chlorzoxazone 6-hydroxylation (r = 0.76) and 4-nitrophenol-hydroxylase (r = 0.91). Both these activities are carried out by CYP2E1. (omega-1) hydroxylase activity was inhibited by ethanol (Ki = 3.5 mM), dimethylsulfoxide and diethyldithiocarbamate. Furthermore, polyclonal antibody directed against rat CYP2E1 inhibited (omega-1)-hydroxylation by more than 90% while it had no effect on the omega-hydroxylation. These results suggest that the (omega-1)-hydroxylation of lauric acid is mediated principally by the CYP2E1 enzyme in rat liver microsomes.