[Effect of the tetrapeptide tuftsin on activity of the monoaminergic system of the brain in experimental pathology].

Single administration of the regulating peptide tuftsin Thr- Lys-Pro-Arg (300 micrograms/kg) was shown to affect the state of the transmitter systems in the brain of rats treated with the sedative drug haloperidol in a total dosage of 15 mg/kg within 30 days. Haloperidol therapy caused reciprocal alterations in the activity of monoamine oxidases A and B, in the levels of dopamine, noradrenaline, serotonin, and 5-hydroxyindolyl acetic acid, as well as a decrease in the rate of depolarization-dependent Ca(2+)-capture in the synaptosomes of the rat brain cortex and neostriatum (N. caudatus); under these conditions tuftsin normalized the parameters studied to a certain extent, which was more pronounced in N. caudatus. The peptide appeared to activate synaptic transfer in the dopaminergic nerve endings and to contribute to balance restoration in the neurotransmitter systems (particularly in the neostriatum) impaired by abnormalities.