Inhibition of entry of some amino acids into the brain, with observations on mental retardation in the aminoacidurias

Abstract

SYSNOPSIS: Abnormally high levels of various amino acids were maintained in the bloodstream of rats, causing saturation of amino acid transport into the brain and partial exclusion from the brain of other amino acids which are necessary for protein synthesis. Excluded amino acids could be made to enter the brain by raising their concentration in the bloodstream. The possible relevance of these findings to improvements in the dietary treatment of some inborn errors of metabolism is discussed.