Immunohistochemical distribution of aldose reductase.

Aldose reductase (AR) has been purified from canine kidneys, and a monospecific antibody against the enzyme prepared. These antibodies were used in an immunohistochemical test to detect tissue sites of aldose reductase in the dog, a species known to develop diabetic lesions morphologically identical to those seen in diabetic patients. Using this method, the enzyme has been demonstrated in numerous cell types, including lens epithelium, aortic endothelium and smooth muscle, Schwann cells of peripheral nerves, and, in the kidney, interstitial cells and cells of Henle's loop and the collecting tubules. Many other cells and tissues, including capillaries throughout the body, lack immunoreactive aldose reductase. The distribution of the immunoreactive enzyme is compatible with a potential role of the enzyme in the aetiology of some complications of diabetes, namely cataract, neuropathy, macroangiopathy and renal papillary necrosis, but not the microvascular complications.