GABA-induced changes of the tissue-specific peptide pool of white rat brain.

Internasal administration of gamma-aminobutyric acid (GABA) induced prolonged behaviour changes and the appearance of three new compounds absent in the brain extracts of control rats. Two peptides associated with GABA administration were isolated and sequenced: Thr-Tyr-Thr-Phe, which corresponds to a gamma-immunoglobulin segment, and Val-Leu, which is present in a great number of proteins, hence its precursor could not be established. The third compound was not amenable to the Edman degradation technique. The data obtained show that the introduction of a neurotransmitter could cause specific changes in the levels of tissue-specific peptide components.