Caloric intake alters the efficiency of catalase mRNA translation in the liver of old female mice.

The free radical theory of aging predicts that calorie restriction, which extends life span, should reduce oxidant damage. In mammals, the oxidative processes centered in the liver are a major source of free radicals. Liver catalase has the dominant role in the intracellular detoxification of hydrogen peroxide. In male rodents, published studies indicate that aging decreases catalase gene transcription and that calorie restriction obviates this effect. In females, published studies are inconsistent, and no molecular mechanisms have been identified. Here we report that, in female mice, aging can lead to an increase in the translational efficiency of hepatic catalase mRNA, and that calorie restriction obviates this effect. Consideration of these results and published studies leads us to propose that the variability in catalase results in females may arise from the small number of studies or from unique aspects of female physiology, perhaps the estrous cycle and its cessation with age.