To study the role of α-actinin in kidney ischemia/reperfusion injury by investigating the changes of α-actinin expression and its distribution in renal tubular epithelial cells (RETs) at different ischemia/reperfusion time stages.

The unilateral renal artery of neonatal SD rats was clamped for 0. 5h, then the kidneys were reperfused by removing the clamp for different time intervals. Immunofluorescent staining was used to show the distribution and expression of α-actinin in renal tubular epithelial cells. The quantities of α-actinin were counted by ImagePlus-Pro system. All data were analyzed with SPSS software.

In the control, α-actinin located mainly in the plasma near the basal and apical membrane. After ischemia for 0. 5h, the distribution of α-actinin around the apical membrane decreased significantly, and some α-actinin could be detected in the lumen. After reperfusion for 2h, no α-actinin could be seen near the apex and those near the basal membrane also decreased, showing a damaged continuity. After reperfusion for 120h, compared with the control the distribution of α-actinin showed no difference in the basal region but reduced in the apical region. After 2h of reperfusion, the expression of α-actinin in the basal region was significantly lower than the control. After 2h and 120h of reperfusion, the expression of α-actinin in the apical region was significantly lower than the control.

Normally α-actinin is located in the plasma near the basal and apical membrane of RETs. Under ischemia/reperfusion injury, its expression and distribution drop down, which may induce the damage of microvilli and the depolarization of integrin of RETs, and thus affects the renal function.