Regulation by delta-sleep-inducing peptide of the neurochemical changes in the brain associated with dopaminergic system hyperactivity.

The influence of a single injection of "delta-sleep-inducing peptide" (DSIP; 30 microg/kg body weight) on neurochemical parameters of rats' brain was studied under the conditions of chronic administration of dopamine analogs inducing DA-system hyperactivity - 50 mg/kg body weight of L-DOPA for 30 days or 2,5 mg/kg body weight of amphetamine for 21 days. The parameters of serotonergic system (MAO A activity, 5-HT, and 5-HIAA contents) and of dopaminergic system (MAO B activity, DA, NA, and HVA contents) were investigated in the cortex and caudate nucleus of control, DA or amphetamine, and DSIP receiving rats. Changes caused by the two DA-system activating drugs had both similarities and differences, and the corrective action of DSIP also had certain peculiarities depending on the pharmacological preparation used for the induction of DA-system hyperactivity and on the investigated brain structure. It is supposed that DSIP action might be based on the activation of serotonergic system that ensures the adaptive behavior of the animals.