Zadesenets I.P. Morphological features of development of coronary vessels and atrioventricular valves of the heart in rat embryogenesis under the influence of heavy metals (anatomical and experimental study). - Qualifying scientific work on the rights of the manuscript.
Dissertation for the degree of Doctor of Philosophy in field of knowledge 22 "Health" in specialty 222 "Medicine". - SI "Dnipropetrovsk Medical Academy of the Ministry of Health of Ukraine", Dnipro, 2020.
The dissertation is devoted to the study of morphological bases of disorders of the general course of embryogenesis and establishment of changes of coronary vessels and atrioventricular valves of rat heart in the prenatal period of ontogenesis under the influence of cadmium salts and under conditions of zinc and selenium citrate correction. The experimental study was performed on laboratory rats, the morphological material of the study were the fetuses and hearts of rat fetuses on the 13th and 20th days of gestation.
The use of anatomical, histological, embryological, morphometric, immunohistochemical and statistical methods made it possible to investigate and analyze the rates of embryonic mortality and the main changes in the morphogenesis of the atrioventricular valves and coronary vessels of the rat heart under normal development and under the influence of cadmium chloride and cadmium citrate (dose 1.0 mg / kg, respectively) during isolated administration and in combination with zinc and selenium citrates (dose 1.5 mg / kg and 0.1 mg / kg, respectively) in conditions of intragastric administration to pregnant female rats throughout pregnancy. The accumulation of cadmium and zinc in the control and in all experimental groups was detected and compared with the help of polyelement analysis by the method of atomic emission with electric arc atomization.
When comparing the embryotropic action of cadmium salts, the most pronounced embryotoxic effect was possessed by the ionic form of cadmium chloride at both studied gestational terms (13th and 20th days). In the groups of combined administration of cadmium with zinc and selenium citrates, a significant decrease in the overall embryonic mortality was obtained in comparison with the group of isolated administration of cadmium chloride.
When calculating the cardiofetal index of fetal rats of the 20th day of development, the highest value of this indicator was obtained for the group of isolated administration of cadmium chloride by reducing the average wet weight of the fetus and increasing the average wet weight of the heart.
According to the results of polyelement analysis of cadmium accumulation in the heart of rat fetuses, it was found that in the group of cadmium citrate the obtained index was 11.3 times higher than in the control group.
When using histological techniques in the group of rats isolated isolation of cadmium chloride perivascular edema and an increase in the thickness of the media of myocardial vessels with a decrease in their inner diameter, as well as increasing the expression of the marker α-SMA in the wall of myocardial vessels. In the group of isolated administration of cadmium citrate, tortuosity of subepicardial vessels and reduction of their internal diameter were recorded.
When quantifying the thickness of the cusps of atrioventricular valves, we obtained the lowest value for the group of rats with cadmium chloride administration. Cadmium citrate led to an increase in the thickness of the cusps.
The novelty of the study and the results obtained.
The effect of nanoaquachelate forms of zinc, selenium and cadmium in selected doses and combinations was studied for the first time. The embryotoxicity of cadmium salts was studied for the first time in isolation and in combination with zinc and selenium citrates on the 13th and 20th days of prenatal development in the simulation of chronic cadmium intoxication. For the first time morphometric data on changes in atrioventricular valves thickness, internal diameters of coronary arteries and ventricular myocardial vessels under the influence of cadmium salts were obtained.
The theoretical and practical significance of the obtained results lies in the fact that the data on embryotoxicity, cardiotoxicity, accumulation of cadmium salts in tissues with different physicochemical properties are studied. The morphometric parameters of the heart of rat embryos (thickness of the atrioventricular valves, inner diameter of the coronary arteries and vessels of the ventricular myocardium) and their changes in isolated intragastric administration of cadmium salts to pregnant female rats throughout the whole period of pregnancy and pregnancy. selenium. The positive effect of zinc citrate on the indicators of embryotoxicity, tissue accumulation, cardiotoxicity of chloride and cadmium citrate was established.
