Immunoelectron microscopic study of plasma protein pathways through the abnormal intestinal vasculature of HgCl2 induced immune disease in brown Norway rats.

Localization of immune deposits (ID) and the pathway of circulating serum proteins through the intestinal vasculature have been studied in 40 Brown Norway (BN) rats poisoned by mercuric chloride, using anti-peroxidase IgG as tracer. ID were found in all vessels but were initially detected along the epithelial basement membrane of villi and in pericytic venules and veins. ID were found in all the layers of the vessel walls. In pericytic or myocytic vessels, no ID were detected outside the adventitial lamina densa. ID trapped non immune IgG. Abnormal pathways were only found in venular capillaries and in pericytic venules with large gaps between endothelial junctions. ID were particularly abundant in these vessels.