title: Caloric restriction affects liver microsomal monooxygenases differentially in aging male rats.
abstract: Caloric restriction (CR) extends life span and retards the onset of physiological changes and pathologies associated with aging, but the underlying mechanisms remain unresolved. This study demonstrates that CR postpones the documented age-related declines in and/or enhances the activity and microsomal concentration of several liver monooxygenases in male rats, i.e., NADPH cytochrome P-450 reductase, total cytochromes P-450. However, the relative concentration of cytochrome P-450b+C did not exhibit statistically significant changes, whereas another isozyme, the male specific P-450h, declined significantly in both ad libitum-fed and CR rats as a function of increasing age. While CR appears to retard age-associated changes in certain liver enzymes, this effect is by no means universal. The hepatic monooxygenases constitute a well-characterized enzyme system in which to examine the perturbation of the aging process by CR.
authors.affiliation: Cell Biology and Aging Section VA Medical Center, San Francisco, CA 94121.
authors.forename: D L
authors.initials: DL
authors.lastname: Schmucker
authors.forename: R K
authors.initials: RK
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Snyder
authors.forename: H
authors.initials: H
authors.lastname: Strobel
authors.forename: U
authors.initials: U
authors.lastname: Marti
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000378:metabolism*; D002149:Energy Intake; D007425:Intracellular Membranes / Q000737:chemistry; D008297:Male; D008862:Microsomes, Liver / Q000737:chemistry / Q000201:enzymology*; D009251:NADPH-Ferrihemoprotein Reductase / Q000032:analysis / Q000378:metabolism*; D011506:Proteins / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D011506:Proteins; D003577:Cytochrome P-450 Enzyme System; D009251:NADPH-Ferrihemoprotein Reductase