Effect of proline-containing oligopeptides on peculiarities of operant conditioning of behavior in outbred rats

Abstract

In experiments on male Wistar rats, the effect of synthetic derivatives of arginine-vasopressin (tetrapeptides N-Ac-DSer-Pro-DArg-Gly-NH2 (I) (1.0 μg/kg, i. n.), N-Ac-Trp -Pro-Arg-Gly-NH2 (II) (1.0 μg/kg, i. n.) on the dynamics of the level of anxiety (LA) and the ability to reproduce operant reactions (OR) against the background of 24-hour deprivation of the paradoxical phase of sleep (REM sleep deprivation) in rats. Statistically, N-Ac-Trp-Pro-Arg-Gly-NH2   significantly ( p < 0.05) reduced the LA of rats exposed to stress, increasing the proportion of individuals in the population that had spent time in the central square of the actometer chamber not less than 10 % of the total duration of actometry. The oligopeptide N-Ac-DSer-Pro-DArg-Gly-NH2 had a statistically significant ( p < 0.05) corrective effect on the ability to reproduce the developed OR of pressing the pedal in rodents (Wistar rats of an unranked population and Wistar individuals with low LA) subjected to REM sleep deprivation. Thus, both studied compounds did not cause cognitive impairment, and N-Ac-DSer-ProDArg-Gly-NH2 improved mnestic functions against the background of REM sleep deprivation. The results of assessing the level of general motor activity indicated the absence of side sedative effects in I (1.0 μg/kg) and II (1.0 μg/kg ‒ at a dose that causes an anxiolytic effect when administered II). The data obtained indicate the anxiolytic effect of N-Ac-Trp-Pro-Arg-GlyNH2, the positive mnemotropic effect of N-Ac-DSer-Pro-DArg-Gly-NH2, and a low likelihood of developing side effects in relation to the central nervous system against the background their applications.