Role of mitochondrial ATP-sensitive potassium channels in attenuation of renal ischemia-reperfusion injury by lidocaine pretreatment in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of mitochondrial ATP-sensitive potassium (mito-KATP) channels in attenuation of renal ischemia-reperfusion (I/R) injury by lidocaine pretreatment in rats.Methods Sixty healthy male Wistar rats,weighing 300-350 g,were randomly assigned into 5 groups (n =12 each) using a random number tablesham operation group (group S); renal I/R group (group I/R); lidocaine pretreatment group (group L) ; 5-HD (a specific blocker of the mito-KATP channel) group and 5-HD + lidocaine pretreatment group (group 5-HD + L).Renal ischemia was induced by occlusion of bilateral renal arteries for 60 min with atraumatic microclips followed by 4 h reperfusion.At 60 min before renal ischemia,lidocaine 5 mg/kg was intravenously injected followed by continuous infusion at 2 mg· kg-1 · h-1 in group L.5-HD 10 mg/kg was injected intraperitoneally at 65 min before ischemia in group 5-HD.In 5-HD + L groups,5-HD 10 mg/kg was injected intraperitoneally at 65 min before ischemia and the other procedures were similar to those previously described in group L.In S and I/R groups,the animals received equal volumes of normal saline instead of lidocaine.Blood samples were obtained at 6 h of reperfusion for determination of serum creatinine (Cr) and urea mitrogen (BUN) concentrations.Bilateral kidneys were removed for determination of mitochondrial membrane potential in the renal tubular epidural cells,malondialdehyde (MDA) content,and superoxide dismutase (SOD) activity and for microscopic examination.Results Compared with group S,the serum Cr and BUN concentrations and MDA content were significantly increased,and SOD activity and mitochondrial membrane potential were decreased in I/R,L,5-HD and 5-HD + L groups (P ＜ 0.05).Compared with group I/R,the serum Cr and BUN concentrations and MDA content were significantly decreased,and SOD activity and mitochondrial membrane potential were increased in L and 5-HD + L groups (P ＜ 0.05),and no significant changes were found in the serum Cr and BUN concentrations,MDA content,SOD activity and mitochondrial membrane potential in group 5-HD (P ＞ 0.05).Compared with group L,the serum Cr and BUN concentrations and MDA content were significantly increased,and SOD activity and mitochondrial membrane potential were decreased in 5-HD + L group (P ＜ 0.05).The pathological changes were significantly reduced in group L as compared with I/R and 5-HD + L groups.Conclusion Mito-KATp channels are involved in reduction of I/R-induced renal injury by lidocaine pretreatment in rats.