[Morphology of the transendothelial pathways of the small intestine lymphatic capillaries in experimental venous congestion].

Ultrastructure of the lymphatic capillaries of the small intestine wall has been studied in 30 normal, 19 control cats and in 56 experimental cats subjected to ligation of the intestinal veins. After ligation of the intestinal veins, in the small intestine lymphatic veins the transporting surface and transport intensity increase. The increase of the former results from formation of the cytolemma folds, invaginations and protrusions of endotheliocytes cytoplasm, as well as from increasing number of pinocytic vesicles and their connections with cytolemma of the cells. As to a more intensive transport in the lymphatic capillaries at the venous congestion, as compared to the normal variability of the transport pathways demonstrates it: intercellular, performed by means of wide interendothelial spaces, and transendothelial, performed by means of a great number of the pinocytic vesicles and vacuoles. The data demonstrate that the wall of the small intestine lymphatic capillaries possesses certain plastisity and high adaptive properties resulting in activation of their drainage function as a response to a disturbed venous outflow of the organ.