Effect of ischemia and reperfusion on enzymes of carbohydrate metabolism in rat kidney

Background: Ischemia results in rapid decline in mitochondrial electron transfer, resulting in decreased ATP levels, and fall in intracellular pH. The purpose of the study was to examine the effects of ischemia and reperfusion on the activities of enzymes of carbohydrate metabolism in rat kidney. Methods: Ischemia was induced by occlusion of the left renal artery for specified times. The activities of Na-KATPase, lactate dehydrogenase (LDH), Malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME), glucose-6-phosphatase (G6Pase), and fructose-1, 6-bisphosphatase (FBPase) were studied in the homogenates of whole (WC), superficial (SCH), and juxtamedullary (JMCH) cortices and medulla (MH). Results: The activities of LDH, G6Pase, FBPase, and ME rapidly increased whereas those of MDH and G6PDH decreased by brief ischemia of 5min both in the cortex and medulla. Prolonged ischemia (15-60 min) caused progressive decrease in the enzyme activities. Reperfusion for 60 min caused complete recovery of the enzyme activities studied. Conclusions: The results demonstrate that activities of carbohydrate metabolism enzymes are restored by short-term reperfusion following 30 min ischemia.