Morphology of Pulmonary Blood Vessels of Young Rats under Conditions of Experimental Alloxan Diabetes

Diabetes mellitus is a disease manifested by chronic hyperglycemia and glucosuria and accompanied by a large number of complications in the cardiovascular and nervous systems. Known complications of diabetes mellitus are angiopathy, neuropathy, nephropathy, retinopathy. Diabetic angiopathy includes generalized defeat of arterioles and capillaries (microangiopathy) and vessels of medium and large caliber (macroangiopathy). Diabetic microangiopathy is a specific complication of diabetes mellitus, typical for type І diabetes. It is manifested by thickening of the basal membrane of capillaries and proliferation of the endothelium and macoangiopathy is considered as an early and common atherosclerosis. Kidney damage arises as a result of microangiopathy of the renal glomeruli vessels. It manifests itself by the capillaries expansion and an increase in the permeability of their basal membranes. Diabetic retinopathy is manifested in vascular changes and retinal tissues – the changes in caliber and vorticity of retinal vessels, microaneurysm, hemorrhage, edema, the presence of solid and soft exudates, glial proliferation, vitreoretinal tract. The purpose of the study is to describe changes in the pulmonary vessels of young rats of the intact group and animals under experimental aloxan diabetes, which lasted from 90 to 180 days. Material and methods. Rats of young age were studied from five to eight months in intact groups and in the corresponding experimental groups with different duration of aloxan diabetes. The following methods for the study of pulmonary tissue were used: histological examination (using van Gyzon staining), scanning electron microscopy and morphometry using the Digimizer 2007 program. The following measurements were made: 1) the thickness of the middle layer of vessels, 2) thickness of vessels externa; 3) glucose oxidase test to determine the level of glucose in venous blood and 4) the level of glycosylated hemoglobin (HbA1c) at 90 days of the experiment to confirm the presence of hyperglycemia in animals. Conclusion. Analyzing changes in pulmonary vessels of rats in the control group (from five to eight months), it can be argued that there occurs sclerosis of the pulmonary arteries with parallel thickening of the muscle layer in tunica media when aging of the body is normal. We found out that since the 90th day of aloxane diabetes the following effects were observed: an increase in the number of myocytes, their size, collagen and elastic fibers in the tunica media and the loose connective tissue in the tunica externa, which indicated intensification in the above processes.