Abstract
Enzymatic and antigen activities of aspartate aminotransferase isozymes in rat fed a diet with or without pyridoxine supplemented were determined. The existence of some inactive forms of the enzyme in the liver and heart from pyridoxine-deficient rat was suggested. The inactive forms in the liver were only partially recovered the enzyme activity by injection with pyridoxine to the deficient rat. The rates of synthesis and degradation of the isozymes in the livers of pyridoxine-deficient and control rats were examined. In the pyridoxine-deficient rat liver, an increased and a very similar rates of the synthesis of cytosolic and mitochondrial enzymes, respectively, were observed. Pyridoxine deficiency did not affected the rate of degradation of mitochondrial enzyme, but it gave very complicated effect on that of cytosolic enzyme; there were at least 2 components with different rates of degradation. The increase in the synthesis of cytosolic enzyme in the deficient rat liver was suggested to be related to an increase in the functional state of glucocorticoid hormone.
