Summary and Comment on Tissue Changes in Vitamin B6Deficiency

Abstract

Publisher Summary Pyridoxal phosphate enzymes have varying degrees of sensitivity to vitamin B 6 depletion. Enzymes involved in the degradation of the S amino acids are impaired in an early stage of the deficiency, whereas liver trarisaminases are little affected by progressive vitamin B 6 deficiency. In comparison with the course of vitamin B 6 deplctiori in rats, the activity of kynureninase was increased largely than kynurenine-a-ketoglutarate transaminasc. In cell particle fractionation, kynureninase occurred only in the supernatant whereas the transaminase occurred mainly in the mitochondria. The apoenzyme synthesis of pyridoxal phosphate containing enzymes appeared to be induced arid regulated by pyridoxal phosphate. Organs with a high protein turnover lose their pyridoxal phosphate enzymes more rapidly by vitamin B 6 depletion than those with a low protein turnover. Correlations exist with cerebral signs resulting from vitamin B 6 depletion and the activity of enzymes dependent upon pyridoxal phosphates. The activation and synthesis of vitamin B 6 dependent enzymes may depend upon the vitamin intake and the activities of these enzymes may control the pathway by which an amino acid will be metabolized.