BLOOD TRANSAMINASE ACTIVITIES IN VITAMIN B6 DEFICIENCY: EFFECT OF DEPLETION AND REPLETION ON THE ERYTHROCYTE ENZYMES

Abstract

To assess the usefulness of the erythrocyte transaminases, glutamic–oxaloacetic and glutamic–pyruvic, in the evaluation of vitamin B₆ nutritional status, the response of these enzymes to repletion following 1, 4, and 10 weeks of vitamin B₆ depletion was compared with that of the plasma and liver transaminases in the rat. The responses of the erythrocyte enzymes reflected the state of vitamin B₆ nutrition most accurately and, unlike the plasma and liver transaminases, were not affected by other factors. Repletion produced a rapid response in the erythrocyte enzymes; however, restoration of control levels appeared to depend on red cell turnover, particularly after prolonged depletion periods. This finding suggests that the apoenzyme, as well as the coenzyme, is depleted during vitamin B₆ deficiency.