Hnatjuk M. S., Protsaylo О. М., Tatarchuk L. V., Gargula T. I.
Abstract. It is known that the removal of large volumes of liver parenchyma can be complicated by postresection portal hypertension, which is characterized by dilation and plethora of the portal hepatic vein, mesenteric veins, varicose veins of the esophagus and stomach, hemorrhoidal veins, gastroesophageal bleeding, splenomegaly, ascites. The purpose of the research – morphometric study of age features of remodeling of the hemomicrocirculatory bad of the large intestine under conditions at postresection portal hypertension. Methods and Material. The vessels of the hemomicrocirculatory bad of large intestine of 60 laboratory mature white male rats, which were divided into 4 groups, were studied by a complex of morphological methods. The group 1 consisted of 15 8-month-old intact rats, the 2- 15 24-month-old animals, the 3 – 15 8-month-old rats with postresection portal hypertension, the 4 – 15 24-month-old experimental animals with postresection portal hypertension. Postresection portal hypertension was simulated by removal of the left and right lateral lobes of the liver (58.1% of its parenchyma). Euthanasia of animals was performed by bloodletting under conditions of thiopental anesthesia 1 month after the start of the experiment. The hemomicrocirculatory bad of the large intestine was studied by injecting its vessels with a mascara-gelatin mixture injected through the abdominal aorta. The diameters of arterioles, and precapillary arterioles, hemocapillaries, capillary venules, venules, vascular density per 1 mm² of colon tissue were morphometrically determined. Quantitative values were processed statistically. Results and Discussion. It was found that the diameter of the arterioles of the intact large intestine in 24-monthold rats decreased by 5.1%, precapillary arterioles – by 5.6%, hemocapillaries – by 4.1% (p<0.05), capillary venules expanded by 4,4%, venules – by 4.7% (p<0.05). Resection of 58.1% of the liver parenchyma led to the development of postresection portal hypertension and changes in struсtura vessels of hemomicrocirculatory bad of the large intestine. At postresection portal hypertension in young animals, the diameter of arterioles decreased statistically significantly (p<0.001) by 32.2%, and in 24-month – by 33.1% (p<0.001), the diameter of precapillary arterioles, respectively, by 34.5% and 34.9% (p<0.001), and diameters hemocapillares by 28.4% and 31.2% (p<0.001). Venous vessels of the hemomicrocirculatory bad (postcapillary venules and venules) dilated in the simulated experimental conditions. Thus, in 8-month-old rats, the diameter of the postcapillary venules increased by 39.2%, and in 24-month-old animals – by 40.1% (p<0.001), and the diameters of the venules, respectively – by 32.4% and 33,1% (p<0.001), the density of microvessels decrease by 28.8% and 32.4% (p<0.001) compared with similar controls. Conclusion. Postresection portal hypertension leads to severe vascular remodeling of the hemomicrocirculatory bad of the large intestine, which is characterized by severe narrowing of arterioles, and precapillary arterioles, hemocapillaries and dilation of capillary venules and venules, decreased tissue density microvessels, foci of infiltration, and sclerosis. Structural changes of vessels of a hemomicrocirculatory dominated in a large intestine of experimental animals of senior age group.
«Bulletin of problems biology and medicine» Issue 1 (159), 2021 year, 201-204 pages, index UDK 616.36-089.87-06:616-091]-092.9
