Influence of portal hypertension on the state of the hemomicrocirculatory level of rat skin: morphological study

Abstract

The effect of portal hypertension on the condition of the hemomicrocirculatory tract of the skin male white nonlinear rats was studied. Hypertension was simulated by applying a ligature to the portal vein according to the conventional method. After 30, 60 and 90 days, skin biopsies were taken from the anterior abdominal wall for optical microscopy examination, which was subjected to routine histological processing. In animals of the control group, which underwent sham surgery, the skin remained unchanged. In rats of the experimental group after 30 days in the basal layer of the epidermis there were cells with signs of degenerative changes. The basement membrane of the epidermis had small areas with thinning and thickening, which in both cases were accompanied by the formation of small and massive leukocyte infiltrates. Its edema was noted, which extended to the papillary and reticular layer of the dermis. Elastic fibers were unchanged. Only 50% of the microvessels looked intact, 20% microvessels were narrowed, and 30% had signs of stagnant hyperemia due to dilatation. After 60 days the epidermis was thinned, in the basal layer the cells with picnotized and displaced to the periphery nucleus were detected. In all studied layers of epidermis, besides reticular layer, expansion of arterioles, venules and capillary loops was observed. After 90 days the epidermis was represented by 3-6 layers of cells, its general refinement was observed due to the reduction of the thickness of the spinous and granular layers with simultaneous thickening of the horny layer. In the papillary layer of the dermis, the number of thin-walled blood vessels was increased. The average diameter of the arterioles of the hypodermis decreased relative to the values on the 60th day. The mean diameter of the arterioles of the subdermal network on the border of the papillary and reticular layers and capillary loops under the basal membrane was reduced what can be a sign of sclerotic changes in the microvessels. The venules diameter remained increased. In arterioles and venules, stasis of the microvessels, edema of their walls, microaneurysm, and venous sacculation were detected. Thus, we believe that the changes in the microvessels of the skin, which are observed in portal hypertension, are the result of hemodynamic disturbances in the tissue, which is a complex chain of hemomicrocirculatory flow to the direct action of hypertension in the portal vein and is a secondary response to systemic vascular damage.