The hypothesis of the present proposal is that reactive oxygen species (ROS) generated by glomeruli and/or infiltrating leukocytes, play an important role in the functional and/or morphological changes in glomerular disease. Conceptually, the hypothesis will be approached by examining the role of ROS in two models of glomerular disease, one in which enhanced intracellular generation of ROS may be important (Adriamycin Nephrotoxicity) and a second model in which ROS generated by infiltrating leukocytes (antiGBM antibody disease) may play an important role in the glomerular disease. In addition, the effect of enzymatically generated ROS on renal function and other biological processes potentially important in glomerular disease will be examined. Summary of proposed work:

I. A single IV injection of Adriamycin in rats causes nephrotic syndrome. Based on the evidence that Adriamycin's cardiotoxicity is related to the production of ROS, I propose to study the role of ROS in Adriamycin's nephrotoxicity as follows: 1) The effect of in vitro addition of Adriamycin on superoxide and hydrogen peroxide generation and lipid peroxidation by microsomes and mitochondria from glomeruli, tubules and cortex will be examined. 2) Since intracellular defenses against ROS are important determinants of toxicity, the specific activity of superoxide dismutase, catalase and glutathione peroxidase in glomeruli, tubules and renal cortex in normal and on adriamycin treated rats will be examined. 3) The effects of scavengers of ROS on adriamycin induced nephrotic syndrome will be examined.

II. In antiGBM antibody disease, neutrophils (heterologous phase) and monocytes (autologous phase) are important mediators of tissue injury. ROS produced by leukocytes have been strongly implicated in leukocyte induced damage in other tissues. The role of ROS in antiGBM antibody disease will be studied by: 1) Examining the effect of the binding of antiGBM antibody to GBM on the generation of ROS by glomerular cells, neutrophils and monocytes. 2) Examining the effect of scavengers of ROS in antiGBM antibody disease.

III. Based on the evidence from other tissues that ROS increase vascular permeability, and affect lysosomal lability and in the glomeruli increase cAMP, the following work is proposed. 1) The effect of intraaortic infusion (above the renal arteries) of enzymes that generate ROS on GFR, RBF and urinary protein will be examined using standard clearance techniques, 2) the mechanisms by which ROS increase cyclic AMP in glomeruli, and 3) the effect of ROS on glomerular lysosomal lability will be examined in in vitro studies.

R01AM028452

1981-08-01

1987-07-31