Effect of castration on the turnover of rat liver alcohol dehydrogenase

Castration increased liver alcohol dehydrogenase activity and enzyme protein in male rats. The turnover of alcohol dehydrogenase determined from the decline in radioactivity present in immunoprecipitated enzyme after injection of NaH¹⁴CO₃ was decreased after castration. The fractional rate of degradation (K_d) for the enzyme was 0.11 · day^-1 in the castrated as compared with 0.13 · day^-1 in the control animals (P < 0.05). The fractional rate of synthesis (K_s) of the enzyme was not affected by castration, while the absolute rate of synthesis was increased slightly. This study shows that a decrease in the rate of degradation is the principal cause for the increase in liver alcohol dehydrogenase following castration.