Effect of aminoguanidin on intestinal ischemia- reperfusion injury in rats

Objective To investigate the effect of aminoguanidin (AG),a selective inhibitor of iNOS,on intestinal ischemia- reperfusion injury in rats,and analyze the correlation of NO with intestine ischemia- reperfusion injury. Methods Thirty- six rats were divided into 6 groups consisting of A group with the ligation of arteriae mesenterica superior for 45 min,B group with same as A group and adding the reperfusion for 90 min,C group with same as A group and adding the reperfusion for 180 min,D group with same as A group and the administration of AG at a dose of 50mg/kg at 10 min be-fore the ligation,E group with same as B group and the administration of AG at 10 min before both of the ligation and reperfusion,and F group with same as C group in intestinal ischemia time and E groups in AG administration,respectively. Plasmic NO content and the synthetic level of iNOS with immune histochemitry were measured,and intestinal pathological changes were scored with Chiu pathological grade under light microscope in all rats of 6 groups. Results There were no significant differences in plasmic NO content,synthetic level of iNOS and pathological changes before and after AG admi- nistration during the ischemia stage (P 0.05 for all). However,above parameters decreased significantly after AG admini-stration during the reperfusion stage (P 0.01 for all). Conclusions NO which is mainly produced by iNOS during is-chemia- reperfusion period plays an important role in causing intestinal ischemia- reperfusion injury. It is feasible that the administration of AG can alleviate the injury by decreasing NO production and its activity.