Some Structural and Chemical Changes in Endocardial Endothelium of Rats in Emotional and Pain Stress Complicated by Hypercholesterolemia

The objective of the research was to study the content of some neutral lipids of endocardial endothelium in rats in relation to structural changes occurring in it, in the co-existence of emotional and pain stress, as well as alimentary hypercholesterolemia. Materials and methods. The electric-impulse model was used for stress modeling. Alimentary hypercholesterolemia was modeled feeding animals an atherogenic diet. The concentration of triacylglycerols, free and esterified cholesterol were examined using the method of thin-layer chromatography performed on silica gel. The concentration of free fatty acids was determined using the radiochemical method. The state of endocardial endothelium was studied with the help of light microscopy; the impression smears obtained from macro preparations of ventricle were analyzed.Results. In co-existence of stress and hypercholesterolemia, significant increase in free cholesterol as well as free fatty acid concentration was noticed. This essentially exceeded the analogical indices under the action of stress only. Structural changes in the endocardium followed by desquamation of separate endotheliocytes were the result of stress reaction. In the action of both pathogenic factors, this process was intensified; layer-by-layer exfoliation of endotheliocytes was observed. Conclusions. In acute emotional and pain stress, changes in lipid spectrum of membrane structures of endocardial endotheliocytes the main manifestation of which is the accumulation of free cholesterol in cells and increase in the levels of free fatty acids take place. The increase in the number of desquamated endothelial cells is the result of stress action as well. Alimentary hypercholesterolemia significantly increases such pathological changes. 

Features of Structural and Functional Organization of the Thyroid Gland in Rats with Microelementosis

This research highlights the study of the influence of combined deficiencies of iodine and copper, selenium or iron on structural and functional features of the thyroid gland (TG). Rats of both groups were kept on iodine-deficient diet for 45 days and received mercazolilum with drinking water until the 15th day of the experiment. Copper deficiency was induced by daily addition of d-penicillamine to drinking water (cuprenil, 100mg/100g body weight, for 21 days). Selenium deficiency was induced by addition of balanced selenium-deficient diet to the basic diet for 45 days. Iron deficiency was induced by daily intraperitoneal administration of iron chelator deferoxamine (desferal, 20mg/100g body weight, for 15 days). Hypofunction of TG secondary to iodine deficiency was found to cause the reduction in thyroid hormones synthesis in comparison with the control group. The follicles of TG were multifarious, often deformed, overstretched by the colloid, the surface area of which was twice (p<0.01) larger than analogous indices in animals of the control group. Hypofunction of TG on the background of combined microelement imbalance caused more expressed violations. So, the elevated serum TSH level by 77.8-88.9% (р<0.05) and index fТ3/fТ4by 65.0-90.0% (р<0.05) were detected in rats with combined deficiency of microelements indicating the decrease in functional ability of TG. Copper, selenium and iron deficiencies were followed by significant increase in the follicular surface area (by 15.7-26.9 %) on the background of the decrease in the height (by 54.6-55.05%) and the surface area of the follicular epithelium (by 33.4-48.6 %), increase in the colloidal density (by 8.2-13.8 %) and index of its accumulation (by 1.8-2.5 times) in comparison with those in animals with isolated iodine deficiency. Thus, combined deficiency of microelements causes more severe structural and functional changes of TG than isolated iodine deficiency