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

Abstract

Neonatal vitamin B₆ deficiency 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 B₆ in sphingolipid metabolism has been the subject of much interest. The amino acid changes are largely explicable by reduced activity of known B₆-requiring apoenzymes.