The effects of dexmedetomidine administrated at two different times in rat renal ischaemia reperfusion injury model

Objective: Ischemia-reperfusion (IR) injury remains the leading cause of acute renal failure. The aim of this experimental study was to investigate the effect of dexmedetomidine in the rat renal IR injury model.Materials and Methods: In the present study, 26 Wistar albino male rats weighing 230-300 g were randomly divided into four groups: the sham group (n=5), the IR group (n=7), the IR/ reperfusion treatment with dexmedetomidine (Dex. R group) (n=7) and the IR/ preischemic treatment with dexmedetomidine (Dex. I group) (n=7) . In the sham group, the abdomen was dissected and then bilateral renal pedicles were exposed. Renal clamping was not applied. For IR group, ischemic acut renal failure was induced by occlusion of the bilateral renal artery and vein for 60 minutes followed by reperfusion for 24 hours. For Dex. R group, the same surgical procedure as in IR group was performed, and dexmedetomidine (100 mcg/kg intraperitoneal) was administrated at the 5th min after reperfusion. For Dex. I group, dexmedetomidine (100 mcg/kg intraperitoneal) was used at the 5th min before ischemia, and then the same surgical procedure as in IR group was performed. At the end of 24th hour, blood samples were drawn from the right atrium, the rats were sacrificed and the left kidney was processed for conventional histopathology.Results: Renal function tests were significantly lower in the sham group when compared with the other groups. The blood urea nitrogen (BUN) levels in group Dex. R and Dex. I were significantly lower than group IR (p=0,015, p=0,043), although urine flow was significantly higher in group Dex.R (p=0,003). The histopathological score of the sham group was significantly lower than the other groups. This score in group IR was significantly higher than the o Dex. R and Dex. I groups.There was no significant difference in histopathological scores between the Dex. R and Dex. I groups.Conclusions: This results indicate that dexmedetomidine reduce histomorphologically the renal injury caused by IR of the kidney. Although, significant difference was not found between two treatment groups, the effect of dexmedetomidine was better when used in reperfusion period. The histomorphological results were supported with biochemical parameters including increased aqueous diuresis and decreased BUN levels.Key words: Kidney, reperfusion, Ischemia-reperfusion, dexmedetomidine