The Role of Adrenoreceptors and Calcium Ions in the Pathogenesis of Endocardium Endothelium Damage of Rats Under Stress Action on the Background of Hypercholesterolemia

Abstract

Abstract. Topicality. Endothelial dysfunction is a key link in the pathogenesis, formation and progression of clinical manifestations of a significant number of cardiovascular system diseases. Some pathogenetic links and structures associated with morphofunctional disorders of cardiac endothelial cells under the stress conditions and its combination with hypercholesterolemia need further examination.
 The aim of the study was to investigate the role of adrenoreceptors and calcium ions (by using of adrenoreceptors and Ca2+-channels blockers) in the pathogenesis of endocardium endothelium damage (by the content of free fatty acids in it and the number of exfoliated cells) as a result of emotional and pain stress action and its influence on the background of hypercholesterolemia.
 Materials and methods of research. An electro-pulse model was used for stress reproduction. The alimentary hypercholesterolemia was simulated by keeping animals on an atherogenic diet during 2 months. To establish the role of the above-mentioned cellular structures in the mechanisms of endothelial cell damage, the following pharmacological drugs were administered to animals: β-adrenoblocker, α-adrenoblocker and Ca2+-channel blocker. The endocardium endothelium state was studied by using light microscopy, by analyzing the smears-imprints from macropreparations of ventricles by counting the number of endothelial cells in them. The content of free fatty acids was determined by radiochemical method.
 Research results. It has been shown that β-adrenoblocker and Ca2+-channel blocker significantly limit the damage of endocardium endothelium of left ventricle under the action of emotional and pain stress, and to a much lesser extent, the same effect has α-adrenoblocker. The protective effect of mentioned preparations under the action of stressor factor against the background of alimentary hypercholesterolemia significantly decreases.
 Conclusions. The obtained data, their analysis and comparison with the results of other experimental and clinical studies allow to make certain conclusions about the pathogenesis of endothelial dysfunction under emotional stress, as well as under conditions of its combination with hypercholesterolemia. In particular, an important link in the development of structural and some biochemical changes of endocardial endothelial cells is the toxic effect of catecholamines, which affect the organism’s functional systems mainly by β-adrenoreceptors (involving Ca2+ ions), to a lesser extent – by α-adrenoreceptors.
 Key words: endocardium, stress, hypercholesterolemia, adrenoreceptors, calcium.