Studies on Copper-Zinc Superoxide Dismutase Expression in Developing Human Liver and Kidney

Abstract

CuZn superoxide dismutase levels were found to be high in developing human kidney and liver compared to some other tissues including lung. In kidney, the enzyme was expressed in proximal and distal tubules, loop of Henle and collecting tubules and after 35 weeks of gestation it appeared to be distributed basally in proximal cells and luminally in distal cells. Glomerular structures were generally negative. CuZn superoxide dismutase was widely expressed in developing liver, with hepatocytes and bile duct epithelium demonstrating positivity. The low level of expression of CuZn superoxide dismutase in the glomerulus compared with the tubules was not expected since intrinsic glomerular cells demonstrate greater production of reactive oxygen species in response to some stimuli than do tubular cells. Expression of this enzyme may be determined by the need to generate hydrogen peroxide.