Transient Hyperglycemia Affects the Extent of Ischemia-Reperfusion-induced Renal Injury in Rats
ABSTRACT Chronic hyperglycemia is known to increase renal injury, particularly during ischemia-reperfusion episodes. The goal of this study was to examine whether transient hyperglycemia during or after renal ischemia-reperfusion increased renal dysfunction.
Male Lewis rats underwent sham operations or unilateral nephrectomies followed by contralateral renal ischemia-reperfusion. Hyperglycemic rats were given 25% dextrose to induce transient hyperglycemia lasting throughout the duration of ischemia (PI rats) or beginning 2 h after initiation of reperfusion (PR rats). Additional vehicle control rats received saline and underwent ischemia-reperfusion surgery as with PI and PR rats. Twenty-five minutes of mild renal ischemia followed by 24 h of reperfusion was induced by occluding the renal artery and vein.
Terminal serum creatinine concentrations were significantly higher in the PI rats when compared with the PR or vehicle control rats. Histology demonstrated significantly increased necrosis in the PI rats relative to PR and control animals. Tissue analyses demonstrated significantly higher heat shock protein 70, heat shock protein 32, and cleaved caspase-3 protein levels in the PI rats. Oxidative stress generated through the xanthine pathway in the PI group was significantly increased compared with the oxidative stress in the PR and vehicle control rats. In contrast, vascular endothelial growth factor and erythropoietin were significantly decreased in the PI rats compared with the PR rats and controls.
Hyperglycemia that occurred during renal ischemia-reperfusion resulted in severe functional injury compared with normoglycemia or with hyperglycemia that occurred after reperfusion. Investigated molecular pathways are more profoundly affected by hyperglycemia that occurs before renal ischemia-reperfusion.
- SourceAvailable from: Justin Sangwook Ko
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- "Hyperglycemia does not require prolonged exposure to exert its deleterious effects. Experimental research has shown that acute hyperglycemia for a transient period increased ischemia reperfusion injury of the liver as well as other organs and impaired microcirculation via oxidative stress and proinflammatory cytokines , , –, which further impair insulin sensitivity and pancreatic insulin secretion . Research in the clinical field also demonstrated the associations between intraoperative hyperglycemia and surgery-related infection and ischemia reperfusion injury in non-hepatic surgeries and liver transplantation , , . "
ABSTRACT: Background Patients undergoing liver resection are at risk for intraoperative hyperglycemia and acute hyperglycemia is known to induce hepatocytes injury. Thus, we aimed to evaluate whether intraoperative hyperglycemia during liver resection is associated with the extent of hepatic injury. Methods This 1 year retrospective observation consecutively enrolled 85 patients undergoing liver resection for hepatocellular carcinoma. Blood glucose concentrations were measured at predetermined time points including every start/end of intermittent hepatic inflow occlusion (IHIO) via arterial blood analysis. Postoperative transaminase concentrations were used as surrogate parameters indicating the extent of surgery-related acute hepatocytes injury. Results Thirty (35.5%) patients developed hyperglycemia (blood glucose > 180 mg/dl) during surgery. Prolonged (≥ 3 rounds) IHIO (odds ratio [OR] 7.34, P = 0.004) was determined as a risk factors for hyperglycemia as well as cirrhosis (OR 4.07, P = 0.022), lower prothrombin time (OR 0.01, P = 0.025), and greater total cholesterol level (OR 1.04, P = 0.003). Hyperglycemia was independently associated with perioperative increase in transaminase concentrations (aspartate transaminase, β 105.1, standard error 41.7, P = 0.014; alanine transaminase, β 81.6, standard error 38.1, P = 0.035). Of note, blood glucose > 160 or 140 mg/dl was not associated with postoperative transaminase concentrations. Conclusions Hyperglycemia during liver resection might be associated with the extent of hepatocytes injury. It would be rational to maintain blood glucose concentration < 180 mg/dl throughout the surgery in consideration of parenchymal disease, coagulation status, lipid profile, and the cumulative hepatic ischemia in patients undergoing liver resection for hepatocellular carcinoma.PLoS ONE 10/2014; 9(10):e109120. DOI:10.1371/journal.pone.0109120 · 3.23 Impact Factor
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- "The detrimental effects of hyperglycemia do not require chronic exposure or preexisting diabetes. Animal models of acute hyperglycemia confirm the deleterious effects of even short episodes of hyperglycemia on cerebral6 and renal ischemia/reperfusion (I/R) injury.7 Proposed mechanisms for the detrimental effects of acute hyperglycemia are increased oxidative stress, an enhanced inflammatory response with cytokine activation8,9 and impaired blood flow with reperfusion.10 "
ABSTRACT: Acute hyperglycemia is known to worsen ischemia/reperfusion (I/R) injury following myocardial infarction and stroke. We investigated whether acute hyperglycemia worsens injury and amplifies the inflammatory response evoked by hepatic I/R. Rats were pretreated with an intraperitoneal injection of 25% glucose or 0.9% sodium chloride (10 ml/kg BW). Subsequently, rats underwent partial (70%) hepatic ischemia for 45 min. After 4 h of reperfusion, hepatic injury, oxidative stress, inflammation, and heat shock protein expression were assessed. Liver injury was increased in the hyperglycemic group with alanine aminotransferase (ALT) and aspartate aminotransferease (AST) serum concentrations of 7,832 +/- 3,374 and 10,677 +/- 4,110 U/L compared to 3,245 +/- 2,009 and 5,386 +/- 3,393 U/L (p < 0.05 vs. control). Hyperglycemic I/R was associated with increased liver nitrotyrosine concentrations and increased neutrophil infiltration. I/R upregulated the protective heat shock proteins HSP32 and HSP70 in control animals, but this protective mechanism was inhibited by hyperglycemia: HSP32 expression decreased from 1.97 +/- 0.89 (control) to 0.46 +/- 0.13 (hyperglycemia), HSP70 expression decreased from 18.99 +/- 11.55 (control) to 3.22 +/- 0.56 (hyperglycemia), (expression normalized to sham, both p < 0.05 vs. control I/R). Acute hyperglycemia worsens hepatic I/R injury by amplifying oxidative stress and the inflammatory response to I/R. The increase in injury is associated with a downregulation of the protective heat shock proteins HSP32 and HSP70.Journal of Gastrointestinal Surgery 12/2009; 14(3):528-35. DOI:10.1007/s11605-009-1112-3 · 2.39 Impact Factor
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ABSTRACT: Hyperglycemia amplifies the inflammatory state after ischemia/reperfusion (I/R), and activated neutrophils have been implicated in the development of I/R-induced renal injuries. D-ribose is a naturally occurring monosaccharide found in all living cells. In this study, we examined whether D-ribose attenuates I/R-induced renal injury by reducing neutrophil activation in rats with transient hyperglycemia. Male Wistar rats were divided into sham (n = 24), control (n = 64), and D-ribose (n = 32) groups. Rats received intraperitoneal injection of glucose (3 g/kg) 30 min before induction of ischemia to induce transient hyperglycemia. Anesthetized rats underwent right nephrectomy and subsequent occlusion of the left renal artery and vein for 45 min. D-ribose (400 mg/kg) was intravenously administered 30 min before induction of ischemia. D-ribose significantly reduced the degree of the I/R-induced increases in renal concentrations of cytokine-induced neutrophil chemoattractant-1 (a chemotactic factor for the activation of neutrophils and chemotaxis to the site of injury) and myeloperoxidase (an indicator of neutrophils infiltration). D-ribose also reduced the I/R-induced increases in serum levels of blood urea nitrogen and creatinine, and improved histological changes, including acute tubular necrosis in the corticomedullary junction fields. These results indicate that D-ribose reduces the I/R-induced acute renal injury in rats with transient hyperglycemia, probably by reducing neutrophil activation. D-ribose might thus be useful for surgical procedures, such as renal transplant surgery, under hyperglycemia.The Tohoku Journal of Experimental Medicine 11/2009; 219(3):215-22. DOI:10.1620/tjem.219.215 · 1.28 Impact Factor