Fluorescent studies on the potential existence of vascular metallic immune complexes

Renal arteriolar thickening, which occurs in response to the presence of cadmium ions, was investigated by fluorescent microscopy. In an acridine orange-stained preparation of the rat kidney, positive fluorescence was observed in the media of renal arterioles following long-term implantation of cadmium wire into the cortex, but was absent in animals similarly treated with copper wire or plastic. The presence of lymphocytic foci around the thickened vessels in cadmium-containing kidneys, together with recent evidence pointing to an association of RNA with immune complex formation, would suggest that the vascular thickening in the presence of cadmium ions is attributable, at least in part, to the mural location of a metallic-originated immune complex.