Abstract
The activity of alcohol dehydrogenase was measured in liver cyto‐solic fractions of male Fischer 344 rats at ages representing young adulthood, middle age, and old age. The activities were 1.7 ± 0.1, 2.3 ± 0.1, and 2.6 ± 0.2 μmol/min/g liver in rats aged 4–5, 14–15, and 24–25 months, respectively. Hepatic alcohol dehydrogenase activity in female rats (3.4 ± 0.2 μmol/min/g liver) was the same in young as in old rats. Castration increased alcohol dehydrogenase activity in young males to levels found in females, and testosterone administration reversed the effect. However, neither physiological nor pharmacological doses of the hormone restored the elevated enzyme activities of old male rats to levels found in young male rats.