The dissertation provides a theoretical generalization and a new solution to the scientific task of establishing the patterns of remodeling of the structures of the chambers and vascular bed of the heart in laboratory sexually mature white male rats in the conditions of postresection portal hypertension and its combination with multiple organ failure. Quantitative morphological parameters of the structures of the chambers of the intact heart and its vascular bed at the organ, tissue, cellular and subcellular levels were determined using a complex of morphological methods in laboratory sexually mature white male rats. It was established that laparotomy did not lead to hemodynamic disorders in the portal hepatic vein system, and did not change the histostructure of the heart chambers. It was found that resection of the left and right lateral lobes of the liver (58.1 % of its parenchyma) led to postresection portal hypertension and pronounced hemodynamic changes in the portal hepatic vein system. The peculiarities of the remodeling of the structures of the heart chambers and their vascular bed at postresection portal hypertension have been elucidated. It has been established that with post-resection portal hypertension there is an uneven, disproportionate hypertrophy and dilation of the heart chambers, in which the relative volumes of the stroma, affected cardiomyocytes, endotheliocytes, stromal-cardiomyocyte ratios increase, capillary-cardiomyocyte ratios and reserve volumes of the ventricles decrease, and the wall thickens arteries, their lumen narrows, the Wogenvoort index increases and the Kernogan index decreases, the secretory activity of the myoendocrine cells of the atria is disturbed.It was discovered that a month after the resection of 58.1 % of the liver parenchyma in the chambers of the heart, expansion, congestion of venous vessels, deformation of their lumen, centers of hypertrophy, dystrophy, necrobiosis of cardiomyocytes, destructive changes in vascular endotheliocytes, stromal structures, and the appearance of lymphoid-histiocytic infiltrates were noted and stroma growth. Changes in the ratios between the types of secretory granules were found: a decrease in the number of young and mature ones and a marked increase in diffusing granules in the myoendocrine cells of the atria were noted. It was found that long-term postresection portal hypertension leads to pronounced morphological restructuring of parts of the myocardium at all levels of its structural organization, and the degree of manifestation of the detected morphological changes is different in the chambers of the heart and dominates in the left ventricle and left atrium when postresection portal hypertension is combined with multiple organ failure.
