State of nervous system functions of Wistar rats when using peptide taftsin-PGP (selank) in restraint stress

Abstract

The aim of the study was to investigate the state of functions of the nervous system of Wistar rats upon application of the peptide taftsin-PGP under conditions of chronic stress. Materials and methods. The experiments were performed on 45 male Wistar rats weighing 200-230 g. Selank peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) was injected intraperitoneally at doses of 80, 250 and 750 μg/kg 15 min before stressor exposure. Animals were divided into 5 groups (n = 9): 1 - control (non-stressed animals injected with saline); 2 - stress (stressed animals injected with saline); 3-5 - stress+taftsin-PGP at doses of 80, 250 and 750 µg/kg. Animals were stressed for 28 days; from days 15 to 28, they were injected with selank/saline. The neurotropic effects of selank were evaluated in the elevated plus-maze, open field (OF) and forced swimming tests. To assess the severity of stress response, the concentration of corticosterone in rat serum was evaluated using enzyme immunoassay. Results. It was found that 28-day immobilisation stress caused disturbances of nervous system functions in the form of increased anxiety, horizontal, vertical, locomotor activity, emotionality and expression of depressive behaviour, as well as increased concentration of corticosterone in blood serum of experimental animals. Taftsin-PGP administration against the background of preliminary stressing (from the 15th to the 28th day of the experiment) contributed to a decrease in the severity of stress-induced behavioural changes in rats: at a dose of 750 µg/kg the peptide had anxiolytic effect, 250 µg/kg - antidepressant effect. At the same time, these changes occurred against the background of a significant decrease in serum corticosterone level. Conclusion. Thus, selank corrects stress-induced changes in the state of nervous system functions under 28-day restraint stress.