The protective effects of amiloride against lung ischemia-reperfusion injury in rats

Objective To investigate the protective effects of amiloride on lung ischemia-reperfusion injury in rats and its possible mechanisms. Methods Fifty-four healthy male Wistar rats were randomly divided into three groups: surgical controls (C group), ischemia-reperfusion group (IR group) and amiloride-pretreated group (A group). At each of three time spots (45 min ischemia, 60 min and 120 min reperfusion), every 6 rats from the groups were sacrificed, collected for plasma sample and the whole right lung. The plasma contents of malondialdehyde (MDA), the wet/dry (W/D) weight ratio of the lung, the activity of myeloperoxidase, and apoptotic index (AI) in lung tissue were determined. Histopathological study of the lung tissue was also performed. Results The plasma contents of MDA, the W/D weight ratio, MPO activity and AI in lung tissue were all significantly increased during reperfusion in IR group but considerably attenuated with Amiloride pretreatment. Pathological examination showed that the IR induced injury was also ameliorated by amiloride pretreament. Conclusion Amiloride treatment before ischemia appeared to protect the lungs against IR induced injury, possibly by inhibited PMN infiltration, reduced production of oxygen radicals and suppressed apoptosis of lung tissue.