The Effects of Intranasal Implantation of Mesenchymal Stem Cells on Nitric Monoxide Levels in the Hippocampus, Control of Cognitive Functions, and Motor Activity in a Model of Cerebral Ischemia in Rats

Hypoxia occurs in situations of disbalance between metabolic needs and the supply of oxygen to organs and tissues of the body. In this regard, tissue hypoxia and ischemia are essential components of the pathogenesis of many diseases. One of the promising areas of research into the mechanisms of ischemia is attempting to weaken the negative effect of hypoxia and ischemia in the brain by using a variety of techniques that activate neuroprotective mechanisms. Here, we aimed to assess the dynamics of restoration of motor activity control in an experimental model of ischemic stroke in rats (cerebral ischemia, CI) after intranasal perineural implantation of mesenchymal stem cells into the receptive field of the olfactory nerve. It was found that the perineural administration of MSCs to rats in the acute period of cerebral ischemia was accompanied by clear signs of recovery of cognitive and motor functions within 1 and 3 days after the operation. On the seventh day after ischemia modeling, rats with the introduction of MSCs had no distinctive features in the control of motor activity compared to the period before the operation in the same rats. In the hippocampus of rats after modeling ischemia, a significant decrease in the content of NO by about 50% relative to the initial level is observed after 1 day. In the hippocampus of rats in which ischemia was modeled with simultaneous intranasal administration of MSC, a significant decrease in NO content by 39% relative to the initial level was also observed after 1 day. The content of NO increases slightly, but the difference in the level of NO relative to ischemic rats was not significant. The copper content in the hippocampus in the rats of these two groups did not change. There was a tendency to increase the efficiency of the antioxidant system 1 day after ischemia in both studied groups, and this effect was more pronounced with intranasal administration of MSC.