Effect of Glyprolines on the Level of Apoptotic and Neurotrophic Factors Under Conditions of “Social” Stress

Abstract

The aim of the article was to study the effect of glyproline neuropeptide compounds Thr–Lys–Pro–Arg–Pro–Gly–Pro (Selank), Pro–Gly–Pro and Pro–Gly–Pro–Leu, on the level of apoptotic factors (caspase-3, caspase-8, the tumor necrosis factor) and neurotrophic factors (the nerve growth factor and the brain neurotrophic factor) in the blood serum of white rats under the experimental modeling of “social” stress.Materials and methods. The experimental studies were carried out on 90 nonlinear white male rats aged 6 months. By the type of behavior, in the process of “social” stress modeling, all the rats were divided into “aggressors” and “victims”. In the study, the following experimental groups (n=10) were formed: control individuals; groups of the rats exposed to stress for 20 days; groups of the animals treated intraperitoneally at the dose of 100 μg/kg/day, starting from the 1st day of the stress factor exposure, with a course of 20 days of glyproline compounds Thr–Lys–Pro–Arg–Pro–Gly–Pro (Selank), Pro–Gly–Pro and Pro–Gly–Pro–Leu. The effect of the compounds on the level of apoptotic and neurotrophic factors was assessed by determining the level of caspase-3, caspase-8, the tumor necrosis factor, the nerve growth factor and the brain neurotrophic factor of white rat blood serum by enzyme immunoassay.Results. According to the results of the study, it was found out that under the conditions of “social” stress, there was an increase in the apoptotic processes accompanied by an increase in the level of caspase-3, caspase-8, TNF-α in the blood serum of white rats, as well as a decrease in the concentration of neurotrophic factors – BDNF and NGF. The administration of giproline compounds against the background of stress, contributed to the restoration of the studied indicators level, which is most likely due to the presence of antiapoptotic and neuroprotective effects in giprolines due to the inhibition of the caspase-dependent cascade of apoptosis reactions, as well as the induction of the synthesis of neurotrophic factors with the antiapoptotic activity.Conclusion. Thus, the administration of glyproline neuropeptide compounds Thr–Lys–Pro–Arg–Pro–Gly–Pro (Selank), Pro–Gly–Pro and Pro–Gly–Pro–Leu under stress conditions, contributes to the restoration of the initiating and effector caspases level, as well as of neurotrophic factors. As a result of the experiment, an anti-apoptotic effect is observed due to the inhibition of the caspase-dependent cascade of reactions, as well as a stress-protective effect is observed due to the restoration of the brain neurotrophic factors level.