Drug-induced changes in the composition of the cerebral free amino acid pool

The effects of insulin, hydroxybutyrate, deoxypyridoxine, chlorpromazine, codeine, morphine, puromycin, and cycloheximide on the composition of the free amino acids in mouse and rat brain were tested. Significant changes occurred in a number of amino acids with most compounds tested; the largest was of alanine (a 50% increase with glucose, a 50% decrease with drugs); histidine was often increased, and the nonessential amino acids were mostly decreased. The pattern of changes was somewhat different in the mouse brain from that in the rat brain. Changes of amino acid levels may participate in the pharmacological action of a number of compounds.