Ischemia caused by the disruption of blood flow results in kidney damage and dysfunction. This study investigated the effects of 30, 60 or 120 minutes of renal ischemia on the levels of glutathione (GSH), the major antioxidant inside cells. Kidneys from anesthetized female Lewis rats (9 months old) were clamped to induce ischemia and then homogenized and separated into cytosolic and mitochondria fractions by differential centrifugation. The levels of GSH and oxidized glutathione (GSSG) in the fractions were measured spectrophotometrically or by capillary electrophoresis. A significant reduction in GSH levels in the cytosol and mitochondria was seen only after the kidney underwent 60 minutes of ischemia. The significant decrease in GSH was accompanied by an increase in the GSSG/GSH ratio and an alteration in the glutathione redox ratio (i.e., GSH/total glutathione). This study demonstrates that an ischemic time of 60 minutes or longer is necessary to cause depletion of GSH levels in the rat kidney. / Department of Physiology and Health Science