Cerebral Lipids and Amino Acids in the Vitamin B6-deficient Suckling Rat1

Neonatal vitamin B6deficiency was established in the rat. Coenzyme levels in brain of suckling rats from dams fed a B6-deficient diet after parturition were determined by the (1-14C)tyrosine-tyrosine apodecarboxylase method and found to be approximately one-third normal in deficient animals 18 days old. Cerebral sphingolipids were reduced 30 to 50% in animals 18 to 20 days old. Minor alterations were observed in glycerophosphatides and plasmalogens. Cystathionine accumulated to 16 times normal levels. Glycine, citrulline, taurine and the branched-chain amino acid levels were also elevated while gamma aminobutyric acid and serine were reduced. The role of vitamin B6in sphingolipid metabolism has been the subject of much interest. The amino acid changes are largely explicable by reduced activity of known B6-requiring apoenzymes.