The immunolocalization of copper-zinc superoxide dismutase in canine tissues.

Copper-zinc superoxide dismutase (CuZn SOD) has been localized in paraffin-embedded sections of formalin-fixed, canine tissues. Staining with the immunoenzyme bridge sequence and the technique utilizing avidin-biotin-peroxidase complex revealed high levels of CuZn SOD in a number of sites. These included hepatocytes, colonic absorptive epithelial cells, ciliated bronchiolar epithelial cells, cells lining the thick ascending limb of Henle's loop in the nephron, endocrine cells producing hormones in pancreatic islets, and neurons in several regions of the central nervous system. The above results are compared with the reported distribution of CuZn SOD as determined by biochemical methods in tissues of various animal species.