Effect of an altered glutathione content on renal ischemic injury.

Renal ischemia and reperfusion have been shown to be associated with an enhanced renal lipid peroxidation. Because glutathione (GSH) serves to protect cells from oxidative stress, the role of GSH in renal ischemia was investigated. The content of renal GSH in the rat declined to 40% of control values during 35 min of renal artery occlusion. Renal GSH levels only partially recovered after 120 min of blood reflow. To assess the significance of this effect, renal GSH levels were altered before occlusion of the renal artery. Rats were treated with either buthionine sulfoximine (BSO) or glutathione monoethylester (GSH-ester) to lower or elevate, respectively, renal GSH levels. The ischemia-induced changes in renal ATP, ADP, and AMP after 35 min of ischemia and 90 min of blood reflow were not affected by prior alteration of renal GSH levels. The ischemia-induced decrease in the respiratory control of isolated cortex mitochondria was also unaffected. In control animals, ischemia of 35 min increased urine flow rate 3.2-fold and decreased GFR to 29% of normal values during the reflow period. Similar changes occurred in kidneys with a depleted GSH level. In kidneys with an elevated GSH, however, both urine flow rate and GFR were decreased to values 50 and 3% of normal, respectively. Morphological analysis demonstrated that ischemia produced an enhanced degree of damage with an increase in cast formation in kidneys pretreated with GSH-ester; however, the ester also produced morphological changes in nonischemic kidneys. The severity of ischemic damage was similar in kidneys with a lower GSH content when compared with controls. We conclude that renal GSH is depleted by ischemia but depletion of renal GSH with BSO before ischemia has no effect on ischemic-induced damage to the kidney. However, ischemic-induced renal dysfunction is enhanced when GSH is elevated with glutathione monoethylester before ischemia.