MORPHOLOGICAL CHANGES OF THE VASCULAR BED AND OTHER RENAL TISSUE COMPONENTS IN PULMONARY TRUNK STENOSIS AND AFTER ITS ELIMINATION (AN EXPERIMENTAL STUDY)
Reversible hemodynamic model of pulmonary trunk stenosis was created in experiments on 34 puppies, 12 of which were later subjected to corrective surgery. Animals of both groups were followed up for 6-12 months. 12 dogs of respective age were used as a control group. The kidneys of animals of all series of experiments were studied using a complex of histological and morphometric methods. It was shown that the constriction of the pulmonary trunk lead to adaptive and pathological remodeling of renal arteries, veins and glomeruli. The former became apparent as the hypertrophic-hyperplastic changes in renal vascular smooth muscle with thickening of the vessel walls, narrowing of the arterial lumen and the remodeling of some of them into the closing type. The latter were manifested by vascular sclerosis of arterial and venous vessels, glomerular collapse and sclerosis. Significant changes were detected in renal tubules and stroma: tubules became atrophic, while stroma underwent sclerosis. All these changes reflect structural remodeling of the kidneys. Elimination of experimental defect triggered the regeneration mechanism resulting in the «reversal» of some changes that developed earlier. During this process, the complete recovery of all renal tissue components was not achieved.