Role of ATP sensitive potassium channel in protective effects of post-conditioning with hydrogen sulfide against hepatic ischemia-reperfusion injury in rats

Abstract

Objective To investigate the role of ATP sensitive potassium (KATP ) channel in protective effects of post-conditioning with hydrogen sulfide against hepatic ischemia-reperfusion (I/R) injury in rats.Methods Thirty adult male SD rats weighing 220-250 g were randomly divided into 5 groups ( n =6 each):sham operation gorup (group S) ; hepatic I/R group; NaHS group; glibenclamide + NaHS group (group G) and 5-hydroxydecanoate (5-HD) + NaHS group (group 5-HD).Hepatic ischemia was produced by 60 min occlusion of left and middle lobe blood flow (about 70％ of the whole liver blood flow) followed by 6 h reperfusion in groups I/R,NaHS,G and 5-HD.NaH S 28 μmol/kg was administered intraperitoneally (IP) at 5 min before reperfusion in groups NaHS,G and 5-HD.Glibenclamide 6 mg/kg and 5-HD 10 mg/kg (KATP channel blockers) were administered IP at 5 min before IP NaHS in groups G and 5-HD respectively.Blood samples were collected at the end of 6 h of reperfusion for measurement of ALT and AST activities and liver specimens were obtained for microscopic examination and measurement of TNF-α content and MPO activity.Results Liver I/R significantly increased ALT,AST and MPO activities and TNF-α concentration in group I/R as compared with group S.NaHS administered at 5 min before reperfusion significantly attenuated hepatic I/R injury.Glibenclamide and 5-HD administered before NaHS could block the protective effect of NaHS against hepatic I/R injury.Conclusion Hydrogen sulfide postconditioning can protect the liver from I/R injury by activating KATP channel. Key words: KATP channels; Hydrogen sulfide; Reperfusion injury; Livers