Induction and regulation of cytochrome P450 K-5 (lauric acid hydroxylase) in rat renal microsomes by starvation.
The effects of starvation on rat renal cytochrome P-450s were studied. The content of spectrally measured cytochrome P-450 in the renal microsomes of male rats increased 2-fold with 72 h starvation, but cytochrome b5 and NADPH-cytochrome P-450 reductase were not induced. 7-Ethoxycoumarin O-dealkylation and aniline hydroxylation activities of the renal microsomes of control male rats were very low but were induced 2.5-3-fold by 72 h starvation. Aminopyrine N-demethylation and lauric acid hydroxylation activities were induced 1.5-2-fold by 72 h starvation. The changes in catalytic activities suggested that the contents of individual cytochrome P-450s in the renal microsomes were altered by starvation. The contents of some cytochrome P-450s were measured by Western blotting. P450 DM (P450IIE1), a typical form of cytochrome P-450 induced by starvation in rat liver, was barely detected in rat kidney and was induced 2-fold by 72 h starvation. P450 K-5, a typical renal cytochrome P-450 and lauric acid hydroxylase, accounted for 81% of the spectrally measured cytochrome P-450 in the renal microsomes of control male rats and was induced 2-fold by 72 h starvation. P450 K-5 was not induced in rat kidney by treatment with chemicals such as acetone or clofibrate. The renal microsomes of male rats contained 6-times as much P450 K-5 as those of female rats. These results suggest that P450 K-5 is regulated by an endocrine factor.
Imaoka
S
S
Laboratory of Chemistry, Osaka City University Medical School, Japan.
Yamaguchi
Y
Y
Funae
Y
Y
D000818:Animals; D042926:Cytochrome P-450 CYP4A; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000096:biosynthesis*; D004790:Enzyme Induction; D005227:Fatty Acids / Q000378:metabolism; D007668:Kidney / Q000201:enzymology*; D008861:Microsomes / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000032:analysis / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000201:enzymology*
D005227:Fatty Acids; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D042926:Cytochrome P-450 CYP4A