OXIDANT ANTIOXIDANT BALANCE IN ISOLATED GLOMERULI AND CULTURED MESANGIAL CELLS/

The mechanisms responsible for age-related glomerular sclerosis (GS) h ave not been clearly identified. The present experiments were aimed at assessing the importance of the oxidant/antioxidant balance in the ea rly stages of this process. For this purpose, the renal function (bioc hemical and clearance studies), some characteristics of isolated glome ruli, and reactive oxygen production (superoxide anion, hydrogen perox ide) as well as the antioxidant ability (superoxide dismutase, catalas e, glutathione peroxidase) of glomeruli and cultured mesangial cells w ere studied in 3- and 18-month-old Fischer 344 rats (YOUNG and OLD rat s, respectively). OLD animals show a normal renal function, increased urine protein excretion, and augmented protein glomerular content, an indirect index of GS. Isolated glomeruli from these rats produced incr eased amounts of superoxide anion and hydrogen peroxide, and catalase activity was increased. The glomerular thiobarbituric acid-reactive su bstances (TEARS) content was higher in OLD than in YOUNG animals. Simi lar results were obtained in cultured mesangial cells. In summary, the present results demonstrate, at an early stage of rat GS development, an association between the functional and structural changes of this process and an increased TEARS content (likely indicative of lipid oxi dative damage) at the glomerular structures as well as in cultured mes angial cells. More extensive studies are needed to confirm the nature of this association. Copyright (C) 1996 Elsevier Science Inc.