Amino-Acid Transport across the Brain Cell Membrane

　When γ-aminobutyric acid was accumulated actively into guinea pig brain cortex slices, P³² turnover of phospholipid fractions，particularly phosphatidic acid fraction in cytoplasmic particulates of the brain slices which was separated by slicic acid column-chromatography was strongly accelerated．And these phenomena were found only with the brain slices, but not on kidney or liver slices．

　The experiments of competitive inhibition for active transport were performed between two kinds of amino-acids．When γ-aminobutyric acid and glutamate, or γ-aminobutyric acid and aspartate, were added simultaneously in the same concentration, these amino-acids were accumulated into brain slices independently without any hindrance．But if γ-aminobutyric acid and β-alanine or glutamate and aspartate were added to the medium at the same time, the accumulation of these amino-acids into brain slices was suppressed considerably．

　The accumulation of γ-aminobutyric acid and glutamate derivertives in brain slices was examined, and an importance of molecular structure of the amino-acid for active transport across the brain cell membrane was discussed．