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Sex-dependent differences in the effects of aging on antioxidant defense mechanisms of rat liver

1991; Elsevier BV; Volume: 1074; Issue: 1 Linguagem: Inglês

10.1016/0304-4165(91)90061-k

1872-8006

Lora E. Rikans, Danny R. Moore, Cynthia D. Snowden,

Vitamin C and Antioxidants Research

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.