We studied the functionality of the antioxidant system in laboratory rat cardiomyocytes and blood under psychoemotional 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.

We have studied the influences that prolonged isolation and disruption of the circadian cycle have on behavioral activity and hormonal status among animals. It has been showed that such conditions result in development of stress, and decreases occur in the activity of both isoforms of rat hippocampus creatine kinase (CK). We have established kinetic parameters (V max , K m ) of this hippocampal enzyme and the nature of the modifications produced by the protocol. It has been suggested that prolonged isolation and disrupted natural circadian cycle result in lower CK-BB activity in animals due to structural changes in the enzyme and a decrease in ATP and creatine substrates. Lowered enzyme activity is accompanied by an accumulation of Ca 2+ ions in the cell, and this might decrease activity of plasma membrane and mitochondrial Ca-ATPase.

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Objectives: Fluorescence spectroscopy which can be used for optical tissue diagnosis of tumor pathology deserves special interest. The purpose of the work was to study blood plasma and tumor tissue of men with different forms of prostate tumors by using laser induced fluorescence. Blood plasma and tumor tissue of the patients with benign hyperplasia of the prostate (BHP), BHP with inflammation, BHP with high grade PIN (BHP with HGPIN) and adenocarcinoma of prostate (CaP) have been studied. Results: In case of blood plasma fluorescence, intensity of the plasma proteins corresponding peak (340-360 nm) was increasing in the following manner: control group → BHP → BHP with HGPIN → CaP. The intensity of the nicotinamide coenzymes correspond peak (440-460 nm) was increased in case of BHP with HGPIN and CaP patients, but decreased in case of BHP, compared to control. In case of tumor tissue, the changes of the collagen peak (390-400 nm) intensity have been revealed in all cases of prostate tumor tissues. These alterations point to altered collagen biosynthesis levels in different tumor tissues, that reflects the structural changes and characteristics of malignant transformation. Also the changes of the nicotinamide coenzymes peak (440-460 nm) intensity in all spectra of tumor tissues were observed. The highest intensity of the peak was observed in the spectra of BHP with HGPIN and in prostate cancer tissue. Conclusions: Alterations of the coenzymes peak intensities perfectly reflect and are in accordance with the specific energy metabolism of prostate epithelial cells. Normalization of fluorescent spectra from different forms of prostate tumor tissues has shown that, each form has typical spectral shape and ratio of fluorescence peaks intensities. L. Ramishvili et al.

Distribution of the Mg²⁺-dependent, HCO₃⁻-stimulated ATPase (HCO₃⁻-ATPase) was investigated in sub-cellular fractions of the tissue of the human thyroid gland. It was found that especially high enzymatic activity is characteristic of mitochondria and the endoplasmic reticulum. Correlation between various pathologies of the thyroid and HCO₃⁻-ATPase activity was demonstrated. The activity was evaluated using the difference between active and passive ATPase. During development of the various pathologies, the sub-cellular fractions of the gland showed uneven alterations of HCO₃⁻-ATPase activity. Intriguingly, the enzyme kinetic parameters are also changed, i.e. in the different pathologies both enzyme activity and its affinity towards bicarbonate ions are altered. This raises the question whether pathology is caused by, or results in, changes in the enzyme at the molecular level.