Genetically determined differences in liver alcohol dehydrogenase activity in male rats

Alcohol dehydrogenase (EC 1.1.1.1) activity was measured in liver extracts from one outbred and three inbred strains of rats. Strain-specific differences in enzyme activity were observed in the adult male rats. The differences appeared as the animals reached puberty. Studies on the enzyme purified from Sprague-Dawley and ACI rats indicate that the enzymes in these strains are identical and that the difference in activity found in liver extracts is due to differences in the amount of enzyme present. Genetic crosses between Sprague-Dawley and ACI rats suggest that the liver content of alcohol dehydrogenase is controlled by an autosomal regulatory locus with the characteristics of a temporal gene.