Study of the role of neurotrophic factors in the regulation of regeneration processes in damaged somatic nerves under the action of semax peptide preparation

The content of neurotrophic factors in damaged somatic nerves under the action of the drug «Semax» was studied and their role in the regulation of regenerative processes in injured nerve conductors was established. It has been shown that intramuscular administration of the drug is accompanied by a significant increase in the level of NGF and NT-3 both in the proximal and distal parts of the nerve. At the same time, there are no significant changes in the quantitative content of neuroregulin-1 against the background of its use. The data obtained suggest that one of the mechanisms of action of Semax is its ability to interact with Schwann cells and stimulate the release of NGF and NT-3, which facilitate the regeneration of damaged axons and do not affect the synthesis of neuroregulin-1. In addition, the study of the quantitative content of individual protein fractions showed that the drug «Semax» has the most pronounced effect on the level of neurofilament-H in both segments of the nerve conductor, which indicates the important role and activation of the mitogen-activated protein kinase (MAPK / ERK) signalling pathway, which regulates processes of cytoskeletal protein synthesis and axon growth. Nevertheless, it was shown that in the variant of the experiment using Semax, there was a decrease in the level of GAP-43, which is a key marker of axonal growth, both in the proximal and distal segments of the nerve. The data obtained most likely indicate that the intramuscular administration of the drug does not affect the processes of axon growth, but is aimed at maintaining the survival of neurons and accelerated restoration of the functional state of nerve fibres, which is also confirmed by the appearance of an action potential and the ability of the nerve to conduct it against the background of the use of the Semax drug.