Endogenous renal nitric oxide metabolism following experimental infrarenal aortic cross-clamp-induced ischaemia-reperfusion injury

Background: Abdominal aortic surgery is associated with marked changes in renal haemodynamics. The aim of this study was to investigate the influence of infrarenal cross-clamping on glomerular filtration rate and endogenous renal nitric oxide metabolism. Methods: Groups of male Wistar rats were subjected to infrarenal aortic cross-clamping followed by reperfusion. Animals were allowed to recover after a left nephrectomy. The glomerular filtration rate of the remaining kidney was measured on the second and seventh day after the procedure before the animal was killed and the remaining kidney harvested. Total nitric oxide synthase (NOS) activity and expression of inducible NOS (iNOS) was determined in renal tissue following 1 h and 7 days of reperfusion. Results: Glomerular filtration rate was impaired on the second and seventh day after operation in all animals subjected to lower torso ischaemia compared with controls (P <0.05). Renal NOS activity was increased at 1 h and 7 days in animals subjected to infrarenal cross-clamping compared to controls (P < 0.01). iNOS was detected in renal tissue of animals subjected to infrarenal aortic cross-clamping on the seventh day after operation. Conclusion: Infrarenal aortic cross-clamping is associated with impairment of renal function in the early postoperative period. There is an increase in endogenous renal nitric oxide metabolism with iNOS expression.