Peptide regulation of specific ligand-receptor interactions of GABA with the plasma membranes of nerve cells

Abstract

Here we studied the role of peptide anxiolytics (Selank and its short fragment, Arg-Pro-Gly-Pro) in the occurrence of direct and indirect changes in the basic parameters of the specific ligand-receptor interactions of γ-aminobutyric acid (GABA) with the plasma membranes of nerve cells in the brain. We found that in the presence of the studied peptides the amount of the specifically bound ligand, [3H] GABA, varied. Preliminary intranasal administration of Selank also induced changes in the number of specific binding sites of [3H] GABA but did not affect the affinity of the receptors. More complex and delayed effects were caused by the preliminary intranasal administration of Arg-Pro-Gly-Pro (RPGP). The data that were obtained in the research also indicate the impact of the peptides on cellular regulatory mechanisms that are not associated with the ligand-receptor interaction of studied peptides in the places of their action. Thus, the biological effects of Selank were apparently due to a combination of the direct modulating action of the peptide on the target receptor and the initiation of the biochemical cellular mechanisms that determine the molecular basis of the physiological effect of the peptide.