Relationship between differential expression of renal AT1 and Mas receptor proteins and kidney injury in mice subjected to limb ischemia-reperfusion / 解放军医学杂志

ABSTRACT

Objective To explore the role of imbalance of local renin angiotensin system (RAS) in renal injury by observing the changes of AT1 and Mas receptor protein expression in renal and the degree of renal injury after limb ischemia-reperfusion (LIR) in mice. Methods The hind legs of ICR mice were rendered ischemic by using a tourniquet to block blood flow. The tourniquet was release after 2 hours to initiate reperfusion. Forty-eight 8-week-old male ICR mice were randomly assigned into 8 groups (6 in each group), including a control group and 7 model groups of 10min, 0.5h, 1h, 2h, 4h, 6h and 12h after reperfusion. Histopathological technique was used to observe morphological changes in renal tissue, and pathological score was assessed. Automatic biochemical analyzer was employed to determine the contents of serum creatinine and urea. Western blotting was performed to determine the expression of AT1 and Mas receptor protein in renal tissue. Results Pathological changes were found in renal tissue of model mice, including interstitial congestion, edema, inflammatory cell infiltration, and epithelial cell degeneration, and the injury score elevated gradually along with the length of reperfusion time. Biochemical results showed that the contents of serum creatinine and urea increased with the prolongation of reperfusion time, reaching the highest level at 4h point.Western blotting showed that the expression of AT1 protein decreased significantly and of Mas receptor protein increased significantly with the prolongation of perfusion time. Conclusion The renal damage is gradually increased after LIR, and the expression imbalance of AT1/Mas receptor proteins may be involved in the damage process.