Vol. 6,No. 3 and 4,1978 Printed in U.S.A. Copper, Cadmium, and the Renal

Investigation of the vasculature of the rat kidney, into which an abnormal trace element, cadmium (wire), was surgically implanted, disclosed consistent medial hypertrophy of the small arteries and arterioles and vascular occlusion. Focal collections of mononuclear cells around affected vessels and the presence of marked birefringence in fields of polarized light suggests the possible forma-tion of an antigen-antibody (immune) complex in response to newly-introduced cadmium. Further support is based upon the observation that similarly implanted copper wire into the rat kidney, which commonly contains trace amounts of this element, yields no positive vascular findings. The emergent role of the environment, in relation to disease, has directed attention to the etiological significance of certain metals. Some trace elements, notably, calcium, cop-per, iron, sodium, and zinc, are customaril