[Brain-specific proteins S 100 and reception of neuromediators by membrane preparations from the rat brain]

Study on specific binding of ligands of various nervous cell membrane neuromediator receptors revealed that brain-specific proteins S100 modulated in a dose-dependent fashion the level of specific binding. Proteins S100 (but not BSA or blood gamma-globulins) changed the Kd values of the ligand-receptor complexes and the number of binding sites. The effects of proteins S100 were specifically blocked by antibodies to S100. Proteins S100 influenced the functions of acetylcholine, serotonin, dopamine, noradrenaline and GABA receptors but not of opiate, imipramine, histamine and benzodiazepine receptors.