STRUCTURAL AND BIOCHEMICAL STUDY OF HEART CHAMBERS AT EXPERIMENTAL ANIMAL INTOXICATION WITH COBALT CHLORIDE

Abstract

Introduction. Cobalt intoxication damages almost all organs and systems of the body. The structural and functional changes in the chambers of heart have not been fully studied. The aim of the study – to experimentally investigate changes in indicators of the antioxidant system, lipid peroxidation, activity of NO-synthases and structures of endotheliocytes of the arteries of the chambers of the heart at cobalt intoxication. Research Methods. Experiments were conducted on 62 sexually mature male rats, which were divided into two groups. The 1 group (30 animals) served as a control, the animals of the 2 group (32 rats) were intragastrically injected with cobalt chloride at a dose of 4 mg/kg for 30 days once a day. One month after the start of the experiment, the experimental animals were euthanized by bloodletting under thiopental anesthesia. In the blood of experimental animals, indicators of antioxidant protection of the body were determined: the activity of superoxide dismutase, catalase, and ceruloplasmin. The content of diene conjugates, active products of thiobarbituric acid, nitrite anion, and the activity of endothelial NO-synthase were determined in the homogenates of the heart chambers. Morphometry of arterial endotheliocytes was performed on micropreparations of heart chambers. Correlation analysis was carried out between the studied quantitative morphometrical parameters and biochemical indicators with determination of the pairwise correlation coefficient. Quantitative indicators were processed statistically. Results and Discussion. Long-term cobalt intoxication of experimental animals leads to a pronounced deterioration of the body’s antioxidant protection, increased lipoperoxidation processes, decreased eNOS activity, nitrite anion level, structural rearrangement of endotheliocytes and damage to their structural components. Correlation analysis revealed strong and significant positive correlations mainly between morphometric parameters of endotheliocytes and indicators of lipid peroxidation and negative correlations between eNOS activity and nitrite anion levels. Conclusions. 1. Intoxication of white rats with cobalt chloride leads to a pronounced decrease in the body’s antioxidant defense, an increase in content of diene conjugates, active products of thiobarbituric acid, a decrease in activity of endothelial NO-synthase, nitrite-anion levels, and damage to the endotheliocytes of arteries of heart chambers. 2. Remodeling of the endothelial cells of arteries of chambers of heart under the influence of cobalt chloride is characterized by an uneven, disproportionate change in the area of endotheliocytes, their nuclei, violations of the relationship between them, and an increase in relative volumes of damaged endotheliocytes, which dominated in the left ventricle. 3. The expression of violations of antioxidant protection, the degree of liperoxidation, the activity of NO-synthase of the organ under study correlates with the degree of structural damage of endotheliocytes.