The effects of the direct ischaemic preconditioning and remote ischaemic preconditioning on renal ischaemia reperfusion injury in rats

Background: Cessation of renal blood flow causes renal ischaemia and restoration of blood flow causes reperfusion in several clinical conditions like shock, renal transplantation, cardiopulmonary bypass, sepsis and urological procedures as partial nephrectomy. One of the methods that can be used to prevent ischaemia reperfusion (IR) injury is ischaemic preconditioning. The aim of this study was to evaluate the effects of remote and direct ischaemic preconditioning (RIP and DIP) in the rat renal IR injury model.Materials and Methods: After obtaining approval from the Instutional Ethics Committee, 28 Wistar Albino male rats weighing approximately 250-300 g were divided into 4 groups. Laparotomy and left renal pedicle dissection were performed to all groups under general anaesthesia. Group I(Sham, n=7): Laparotomy and left renal pedicle dissection were performed but nothing else was done. Group II (IR, n=7): After 45 minutes of left renal pedicle occlusion, 4 hours of reperfusion was performed. Group III (DIP+IR, n=7): After 4 cycles of ischemic preconditioning applied to left kidney, renal IR was performed. Group IV (RIP+IR, n=7): After 3 cycles of ischemic preconditioning applied to left hind leg, renal IR was performed. Durations of anaesthesia were equal in all groups. All rats were sacrificed and the left kidney was processed for conventional histopathology.Results: The histopathological injury score of kidney was significantly lower in the sham group compared with the other groups. The injury score of IR group was significantly higher than the DIP+IR and RIP+IR groups. In RIP+IR group, injury score for erythrocyte extravasation was found significantly lower than the DIP+IR group.Conclusions: In the present study, it was demonstrated that both DIP and RIP decreased renal IR injury but RIP was found more effective than DIP. This protective affect needs more detailed further experimental and clinical studies.Key words: Kidney, reperfusion injury, ischaemic preconditioning.