CYTOCHROME-P450 4A AND 2E1 EXPRESSION IN HUMAN KIDNEY MICROSOMES

Laurate and arachidonate omega and (omega-1)-hydroxylase activities, c ytochrome P450 2E1 (CYP2E1), and CYP4A content were measured in 18 hum an kidney microsomal samples. The rates of laurate and arachidonate we re found to be very different from those measured in human liver sampl es, with a laurate omega/omega-1 ratio of approximately 22 in human ki dney vs 0.75 in human liver. Immunoblot analysis of the 18 human kidne y microsomal samples identified 1 CYP4A electrophoretic band, but CYP2 E1 was not detectable in human kidney, contrary to liver. Laurate and arachidonate omega-hydroxylase activities were significantly correlate d with CYF4A content (r = 0.86 and 0.75, respectively). Polyclonal ant irat CYP2E1 antibody did not affect omega-hydroxylase activity, wherea s the polyclonal antirat CYP4A1 antibody inhibited it by 60%. These re sults suggest that, in contrast to other species, human kidney microso mes do not contain significant amounts of CYPZE1, but possess CYP4A an d fatty acid omega-hydroxylase activity. (C) 1997 Elsevier Science Inc .