Increased rat liver homogenate, mitochondrial, and cytosolic aspartate aminotransferase activity in acute carbon tetrachloride poisoning.

Rat liver homogenate, subcellular fractions, and sera were assayed for aspartate aminotransferase 24 h after the administration of carbon tetrachloride. Enzyme activity per total liver per gram initial body weight was significantly increased in the homogenate, and in the mitochondrial and cytosolic fractions. Protein content per total liver per gram initial body weight was also increased so that the specific activity of the enzyme was unchanged. Enzyme activity per gram liver wet weight was decreased consistent with hepatomegaly, edema, and dilution of enzyme. Enzyme and isoenzyme activities of serum were increased. These findings support the hypothesis that increased synthesis may be a source of increased serum aspartate aminotransferase and its isoenzymes as a response to hepatocellular injury.