Alcohol dehydrogenase activity in the rats liver of different portion, sex and age

Alcohol dehydrogenase (ADH) activity and protein content in the liver of SD rats were determined to clarify the differences in liver portion, sex and age. 1) ADH activity in each liver portion was not identical. ADH activity and protein content showed maximum values in the lobus hepatis sinistra lateralis. Both values of ADH activity and protein content in the processus caudatus and processus papillaris were significantly smaller than those in other portions. 2) ADH activity and total ADH activity in the liver of female rats were 2 times and 1.5 times higher than those of male rats, respectively. 3) ADH activity increased lineally from birth to about 12 days and reached the adult level 2 weeks from birth. Total ADH activity increased sigmoidally with postnatal days. The Michaelis constants for ethanol and NAD in rats from 3 to 215 days from birth were constant. The results indicate that the developmental change in ADH activity is attributed to the increase in the specific activity and not to the change in the affinity.