title: Sex-dependent differences in the effects of aging on antioxidant defense mechanisms of rat liver.
abstract: Information about age-related factors that influence sensitivity to hepatotoxic injury is important to geriatric medicine and environmental health. The purpose of the present study was to determine whether age-associated changes occur in hepatic antioxidant defense mechanisms of male and female Fischer 344 rats. Liver homogenates and post-mitochondrial supernatant fractions from rats aged 4, 14, 24 and 29 months were analyzed for antioxidant enzyme activities and for vitamin E and malondialdehyde content. Age-associated changes in catalase and glutathione reductase activities were observed that could be described as sex-determined differences that disappeared in old age. Cytosolic superoxide dismutase and glutathione peroxidase activities displayed sex-dependent variations in activity but were unaffected by aging. Hepatic vitamin E concentrations were lower in male rats than in female malondialdehyde concentrations also were lower in males than in females; malondialdehyde content increased in old males and decreased in old females. The results indicate that age-associated changes in enzymatic and nonenzymatic antioxidant defense mechanisms of rat liver are sex-dependent. In addition, comparison with findings from other studies in rats suggests that the effects of aging may also depend on the strain of rat.
authors.affiliation: Department of Pharmacology, College of Medicine, University of Oklahoma, Oklahoma City.
authors.forename: L E
authors.initials: LE
authors.lastname: Rikans
authors.forename: D R
authors.initials: DR
authors.lastname: Moore
authors.forename: C D
authors.initials: CD
authors.lastname: Snowden
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001835:Body Weight; D002374:Catalase / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009929:Organ Size; D010084:Oxidation-Reduction; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D012727:Sex Characteristics; D013482:Superoxide Dismutase / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism
chemical_list: D000975:Antioxidants; D011506:Proteins; D014810:Vitamin E; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase