ABSTRACT
Objective To evaluate the effects of autophagy on contrast-induced acute kidney injury (CI-AKI) in rat models.Methods Eighteen male rats were divided into control group (Con),CI-AKI group (CI-AKI) and rapamycin-pretreated group (Rapa).In the CI-AKI group,CI-AKI was induced by intraperitoneal injection of iohexol (12.25 g/kg I).In the Rapa group,rapamycin was given by intraperitoneal injection with a dose of 5 mg/(kg ·d) for consecutive 7 days,and then injected with iohexol (12.25 g/kg I).Rats in the Con group were injected by the same dose of saline.The renal function,renal histopathology,and the levels of LC3 Ⅱ / Ⅰ and Beclin-1 as well as catalase (CAT) in the kidneys of rats were evaluated one day after the injection.Results Compared with the Con group,serum creatinine in the CI-AKI group was significantly increased ((239.93±27.00)μmol/L) vs (51.70±10.59) μmol/L,P＜0.05),and the content of CAT was significantly decreased ((14.86 ± 0.32) U/mg vs (18.72±1.46) U/mg,P＜0.05).In the CI-AKI group,renal tubules were severely injured,and the expression of autophagy-related proteins LC3 Ⅲ / Ⅰ and Beclin-1 in renal tissue was increased.Compared with the CI-AKI group,the pretreatment of rapamycin (Rapa group) increased the expression of LC3 Ⅱ / Ⅰ and Beclin-1 as well as the content of CAT in renal tissue ((17.62±1.86) U/mg vs (14.86±0.32) U/mg,P＜0.05),and inhibited the increase of contrast-induced serum creatinine ((187.62± 47.76) μmol/L vs (239.93±27.00) μmol/L,P＜0.05) and renal tubule injury.Conclusions The results showed that contrast administration can induce autophagy activation in kidneys,while enhancing autophagy can attenuate contrast-induced oxidative stress injury and related renal injury.