ALTERATIONS IN BRAIN CREATINE CONCENTRATIONS UNDER LONG-TERM SOCIAL ISOLATION (EXPERIMENTAL STUDY)

Stress represents one of the main problems of modern humanity. This study was done for understanding more clearly alterations in creatine content of the brain under psycho-emotional stress induced by long-term social isolation. It was shown that under 30 days social isolation creatine amount in the brain was arisen, while decreasing concentrations of synthesizing enzymes (AGAT, GAMT) and creatine transporter protein (CrT). Another important point was that such changes were accompanied by down-regulation of creatine kinase (CK), therefore the enzyme's concentration was lowered. In addition, it was observed that content of phosphocreatine (PCr) and ATP were also reduced, thus indicating down-regulation of energy metabolism of brain that is really a crucial point for its normal functioning. To sum up the results it can be underlined that long-term social isolation has negative influence on energy metabolism of brain; and as a result reduce ATP content, while increase of free creatine concentration, supposedly maintaining maximal balance for ATP amount, but here must be also noted that up-regulated oxidative pathways might have impact on blood brain barrier, resulting on its permeability.

Long-lasting stress, quantitative changes in nitric oxide concentration and functional state of brain mitochondria

We have studied biochemical changes occurring in brain cell mitochondria of white rats on the background of stress induced by 30-day isolation and disruption of circadian rhythms. It was ascertained that due to long-lasting stress, there occurs activation of oxidative processes in mitochondria as well as inhibition of anti-oxidant system activity, causing development of energy deficiency in brain cells. The above-mentioned biochemical processes become the reason for activation and opening of the mitochondrial permeability transition pore (MPTP), which, in its turn, signals the start of neuroapoptosis and various neurodegenerative processes.

Functional state of rat cardiomyocytes and blood antioxidant system under psycho-emotional stress

We studied the functionality of the antioxidant system in laboratory rat cardiomyocytes and blood under psycho-emotional stress. It was found that 40-day isolation and violation of diurnal cycle among the animals were accompanied by the intensification of lipid peroxidation process and marked with a reduced activity of antioxidant system enzymes, such as catalase and superoxide dismutase activity. The results suggested that psycho-emotional stress was accompanied by oxidative stress, causing a reduction in the intensity of energy metabolism in cardiomyocytes, which was further strengthened by the fact that the activity of the enzymes involved in ATP synthesis in mitochondria was reduced. Based on the results, we proposed that psychological stress is one of the factors contributing to the development of various cardiac diseases.