Effect of free radical scavenger on c-jun activation in rats with crush syndrome.

OBJECTIVES

To evaluate the relationship between reactive oxygen species (ROS)-mediated kidney injuries and Jun N-terminal kinase (JNK) activity and the therapeutic effects of tempol in crush syndrome (CS) model rats.

METHODS

Male Wister rats were randomly divided into sham operation group (SOG), CS groups (CS6G, CS12G and CS24G) and tempol treatment group (TG, a ROS scavenger). CS model rats were established by crushing the hind limbs of rats with 15 kg pressure for 6 hours, and inferior caval vein blood and kidney samples were harvested at 6, 12, 24 hours after removing crush pressure. In TG, 100 mg/kg tempol was intraperitoneally injected into CS model rats after withdraw of crush pressure. In SOG, rats were fixed on the board without any crush pressure. The activation of c-jun was determined by western blotting. Serological parameters and the content of malondialdehyde (MDA) in kidney tissues were determined by standard methods.

RESULTS

Acute kidney injury reached the peak at 12 hours after the crush pressure. Compared with SOG, the content of phosphorylated c-jun was significantly higher in CSG and TG (p < 0.05), and the content of phosphorylated c-jun in the CSG was significantly higher than that in TG (p < 0.05). Interestingly, the changes of the MDA content in the kidney tissues of the 3 groups were similar to the changes of phosphorylated c-jun content.

CONCLUSION

ROS-mediated phosphorylation of c-jun may play important roles in the acute kidney injury of CS rats. Tempol can inhibit the phosphorylation of c-jun and alleviate the acute kidney injury.