Renal damage in rats induced by myocardial ischemia/reperfusion: Role of nitric oxide.
BACKGROUND
It has been demonstrated that myocardial ischemia/reperfusion (MI/R) causes renal damage. However, the mechanism underlying this damage in kidneys during revascularization of myocardium is unclear. Direct renal ischemia/reperfusion has been implicated in the induction of inducible nitric oxide synthase (iNOS) that leads to increase production of nitric oxide (NO). Recently, excessive production of NO has been found to be involved in causing renal injury by formatting peroxinitrite (ONOO(-)). The aim of this study was to investigate whether NO has a role in this damage, using aminoguanidine (AMG), a known iNOS inhibitor and an antioxidant, in rats undergoing MI/R.


METHODS
Male Wistar rats were used for the experiments (n = 7 each group). In the MI/R group, the left coronary artery was occluded for 30 min and then reperfused for 120 min; the same procedure was used for the AMG group, with the additional step of AMG (200 mg/kg) administered 10 min prior to ischemia. A control group underwent sham operation. At the end of the reperfusion period, all rats were killed and their kidneys removed for biochemical determination and histopathological analysis.


RESULTS
Myocardial ischemia/reperfusion in the rat kidney was accompanied by a significant increase in malondialdehyde and NO production, and a decrease in glutathione content. Administration of AMG reduced malondialdehyde and NO production and prevented depletion of glutathione content. These beneficial changes in the biochemical parameters were also associated with parallel changes in histopathological appearance.


CONCLUSIONS
These findings suggest that MI/R plays a causal role in kidney injury and AMG exerts renal-protective effects, probably by inhibiting NO production and antioxidant activities.
Parlakpinar
Hakan
H
Department of Pharmacology, Inonu University, Malatya, Turkey.
Ozer
Mehmet Kaya
MK
Cicek
Ekrem
E
Cicek
Ekrerm
E
Cigremis
Yilmaz
Y
Vardi
Nigar
N
Acet
Ahmet
A
D000818:Animals; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007674:Kidney Diseases / Q000209:etiology* / Q000378:metabolism / Q000517:prevention & control; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000150:complications* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012720:Severity of Illness Index
D004791:Enzyme Inhibitors; D006146:Guanidines; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; C004479:pimagedine