SOME EFFECTS OF DIETARY VITAMIN B₆ DEFICIENCY AND 4‐DEOXYPYRIDOXINE ON γ‐AMINOBUTYRIC ACID METABOLISM IN RAT BRAIN

Abstract

Abstract— Investigations of the respective effects of dietary vitamin B 6 deficiency and 4‐deoxypyridoxine (a vitamin B 6 antagonist) on GABA metabolism in rat brain have been carried out. No convulsions were observed in rats subjected to either treatment. GABA levels were lowered by both treatments, the greatest diminutions being found with the dietary deficiency. Glutamic acid decarboxylase activity was reduced under both conditions, but the loss of activity in the B 6 deficiency experiments could be attributed to cofactor depletion, whereas in the deoxypyridoxine experiments the loss of activity appears to be due to lower levels of available apoenzyme. The activity of GABA‐transaminase was not affected by deoxypyridoxine treatment and only moderately reduced in the B.5 deficient animals.