Morphological Features of the Structural Rearrangement of the Hemomicrocirculatory Bed of the Heart Chambers in Diabetes and Post-Resection Pulmonary Hypertension

Damage to the cardiovascular system and diabetes are recognized as the most common global pathologies that often lead to disability and premature death. Foreign and domestic scientists believe that the study of the structure of the human heart and experimental animals are important social, medical and biological directions in connection with the wide spread and growth of cardiovascular diseases and various types of diabetes.Aim. To carry out a morphometric assessment of the features of the structural rearrangement of the hemomicrocirculatory channel of the heart chambers in diabetes and post-resection pulmonary hypertension.Material and methods. The hearts of 48 white male rats, which were divided into three groups, were morphologically studied. The 1st group included 12 intact animals, the 2nd – 12 rats with experimental streptozotocin- induced diabetes, the 3rd – 12 experimental animals with post-resection pulmonary hypertension, the 4th – 12 rats with experimental streptozotocin- induced diabetes and post-resection pulmonary hypertension. The model of experimental diabetes was reproduced by injecting rats with streptozotocin intraperitoneally once at a dose of 50 mg/kg, having previously dissolved it in 0.1 M citrate buff er solution (pH-4.5). Postresection pulmonary hypertension in experimental animals was modeled by right- sided pulmonectomy. Animals were euthanized by bloodletting under thiopental anesthesia 28 days after the start of the experiment. Pieces were cut from the ventricles of the heart, which were fi xed in a 10 % formalin solution, passed through ethyl alcohols of increasing concentration and placed in paraffi n. Microtome sections after depara ffi nization were stained with various dyes. In the left and right ventricles of the heart, the diameters of the studied structures were measured: arterioles, precapillary arterioles, capillaries, postcapillary venules, venules. Quantitative indicators were processed statistically.The results. During the morphological and morphometric studies of the hemomicrocirculatory bed of the ventricles of the heart in conditions of diabetes and post-resection pulmonary hypertension, changes in the quantitative morphological indicators of the elements of the studied heart bed were observed compared to the control ones. The diameter of arterioles of the right ventricle in streptozotocin-i nduced diabetes statistically signifi cantly (p<0.001) decreased by 4.2 %, in post-resection pulmonary hypertension – by 19.9 % (p<0.001), in combined lesions (diabetes and pulmonary hypertension) this morphometric indicator increased respectively – by 30.9 % (р<0.001). It should be noted that the diameter of the hemocapillaries of the right ventricle decreased by 4.7 % with a signifi cant diff erence (p<0.01) in the second group of observations, and by 18.8 % and 30.1 % in post-resection pulmonary arterial hypertension and combined damage. which indicated deterioration of blood supply to the right ventricle.In the simulated experimental conditions, the diameter of the venule of the hemomicrocirculatory channel of the right ventricle of the heart also increased signifi cantly. Thus, in the second studied group of animals (with streptozotocin- induced diabetes), the diameter of the venules was statistically signifi cantly (p<0.001) larger by 3.2 %. In the 3rd experimental group, the diameter of the studied venules of the right ventricle in post-resection pulmonary hypertension changed more. At the same time, the indicated quantitative morphological indicator increased by 16.8 % (р<0.001). In the 4th group of observations (when post-resection pulmonary hypertension is combined with diabetes), the obtained results exceeded the similar control indicator by 24.7 % (р<0.001), which indicated a violation of blood outfl ow in the postcapillary area of the hemomicrocirculatory channel of the right ventricle.Conclusion. Diabetes mellitus and post-resection pulmonary hypertension lead to a pronounced structural rearrangement of the hemomicrocirculatory bed and other structural components of the heart. The detected pathomorphological changes dominated in the right ventricle in post-resection pulmonary hypertension in combination with diabetes.