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

Background: Abdominal aortic surgery is associated with marked changes in r enal haemodynamics. The aim of this study was to investigate the influence of infrarenal cross-clamping on glomerular filtration rate and endogenous r enal nitric oxide metabolism. Methods: Groups of male Wistar rats were subjected to infrarenal aortic cro ss-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 a nimal was killed and the remaining kidney harvested. Total nitric oxide syn thase (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 compa red 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 infr arenal 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 i n endogenous renal nitric oxide metabolism with iNOS expression.