Modulation of cytochrome P-450 induction by long-term food restriction in male rats.
The influence of food restriction (FR) on the induction of liver microsomal cytochrome P-450 (P-450) was examined in rats, FR by 40% for 6 weeks caused increase in the levels of P-450, cytochrome b5 (b5), NADPH P-450 reductase, NADH b5 reductase, P-450 dependent testosterone 6 beta-, 16 alpha- and 16 beta-hydroxylases (P < 0.05). Treatment of 3-methylcholanthrene (MC) to food restricted rats (FR rats) induced more P-450, but phenobarbital (PB) induced it less. MC-inducible P-450 from FR rats did not increase its specific ethoxycoumarin O-deethylase activity but it increased testosterone 2 alpha-hydroxylase activity, and the maximum absorption of its CO complex was shifted from 448 nm to 450 nm. PB-inducible P-450 showed less increase in the activities of its specific benzphetamine N-demethylase and it rather significantly decreased testosterone 16 alpha-hydroxylase activity (P < 0.05). These results indicate that the drugs did not induce their unique types of P-450 in FR rats. Such alterations in P-450 induction in FR rats seem to be closely related to the level of P-450 and its related components enhanced by FR, and it could result in modulation of mixed function oxidase system.
Sohn
H O
HO
Laboratory of Biochemistry, Korea Ginseng and Tobacco Research Institute, Taejon.
Lim
H B
HB
Lee
Y G
YG
Lee
D W
DW
Lee
K B
KB
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D003579:Cytochrome Reductases / Q000378:metabolism; D042966:Cytochrome-B(5) Reductase; D015786:Cytochromes b5 / Q000378:metabolism; D002149:Energy Intake; D008297:Male; D008748:Methylcholanthrene; D008862:Microsomes, Liver / Q000201:enzymology*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D010634:Phenobarbital; D051381:Rats; D017207:Rats, Sprague-Dawley; D039181:Steroid 16-alpha-Hydroxylase; D013250:Steroid Hydroxylases / Q000378:metabolism; D013997:Time Factors
D008748:Methylcholanthrene; D015786:Cytochromes b5; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D039181:Steroid 16-alpha-Hydroxylase; D003579:Cytochrome Reductases; D042966:Cytochrome-B(5) Reductase; D009251:NADPH-Ferrihemoprotein Reductase; D010634:Phenobarbital