Degawa M, Namiki M, Miura S, Ueno H, Hashimoto Y
Department of Hygienic Chemistry, Tohoku University, Sendai, Japan.
Biochem Biophys Res Commun. 1988 Apr 29;152(2):843-8. doi: 10.1016/s0006-291x(88)80115-3.
Renal microsomes from male mice (BALB/c, DBA/2 and BALB/c x DBA/2 F1) showed about 10-fold greater activity for mediating mutagenic activation of 3-methoxy-4-aminoazobenzene (3-MeO-AAB) toward Salmonella typhimurium TA98 than did the corresponding hepatic microsomes, as compared on the basis of nmol of microsomal cytochrome P-450. On the other hand, female renal microsomes and other extrahepatic microsomes (lung, small intestine and colon) in both sexes of mice showed little or no activity for converting 3-MeO-AAB to mutagen(s). The mutagenic activation of 3-MeO-AAB with the male renal enzyme(s) was definitely inhibited by cytochrome P-450 inhibitors, 7,8-benzoflavone and SKF 525A. All these findings suggest that in mice, there is a male-specific renal 3-MeO-AAB activation enzyme(s), a cytochrome P-450 isozyme(s), which is different, at least in proportion and/or in nature, from hepatic cytochrome P-450 isozymes.
