Protective effect of intermedin on renal ischemia reperfusion injury and its mechanism / 中华肾脏病杂志

ABSTRACT

Objective To investigate the protective effect of intermedin(IMD)on renal ischemia reperfusion injury(IRI)and its mechanism. Methods A total of twenty-four male Wistar rats were randomly divided into four groups control group, IRI group, empty plasmid group and IMD group. After remove of right kidney, plasmid was transfected into the kidney by ultrasonic microbubbles technology, and IRI model was made after 1 week. Renal pathology was observed by PAS staining. Renal tissue superoxide dismutase(SOD), myeloperoxidase(MPO), caspase-3 activity, and malondialdehyde(MDA)content were detected by colorimetric method. The intercellular cell adhesion molecule-1(ICAM-1), endothelin 1(ET-1)and P-selection expression of renal tissue were detected by immunohistochemical method. Apoptosis of renal tubular cell was detected by TUNEL.Results Compared with control group, tubulointerstitial pathological injury was significant aggravated in IRI group(P<0.01);compared with IRI group, IMD pretreatment significantly alleviated the degree of renal injury(P<0.01). Compared with control group, in IRI group, SOD activity was significantly decreased(P<0.05), MPO activity, caspase-3 activity, MDA production and the expression of ICAM-1, P-selection, ET-1 were increased significantly(all P< 0.01). Compared with IRI group, IMD pretreatment significantly increased SOD activity(P <0.05), decreased the MPO activity, caspase-3 activity, MDA production and the expression of ICAM-1, P-selection, ET-1 (all P<0.01). The apoptosis rate of renal tubular epithelial cells in IRI group was significantly higher than that in control group(34.83%±8.75% vs 3.33%±0.47%, P<0.01), while the apoptosis rate of IMD group(20.67%±7.71%)was significantly lower than that of IRI group. There was no difference of above indexes between empty plasmid group and IRI group. Conclusions IMD pretreatment protects against renal IRI. The mechanism may be at least partly related to the clearance of oxygen free radicals, the improvement of lipid peroxidation, inflammatory cell infiltration and cell apoptosis, leading to the decrease of the production of reactive oxygen species caused by oxidative stress.