Changes in HO-1, HSP70 and iNOS Expressions in the Rat Liver after Remote Ischemic Preconditioning

Jeon, Su Kyung; Seo, Youn Kyoung; Paik, Doo Jin

Abstract

Ischemic preconditioning (IP), short pre-treatment sublethal ischemia, induces a state of protection against subsequent prolonged ischemia-reperfusion. The purpose of this study was to investigate the expression of HO-1, HSP70, and iNOS proteins in the liver subjected to the courses of reperfusion after repetitive cycles of remote IP in the rat. Using thirty five week-old rats, the remote preconditioning was undertaken by vascular clamp occlusion of blood flow to one hindlimb, with 3 and 10 cycles of 5 minutes occlusion followed by 5 minutes reperfusion. The liver was removed 0, 3, 6, 24, and 72 hours of reperfusion after remote IP and assayed by immunohistochemical staining and Western blotting analyses for anti-HO-1, anti-HSP70, and anti-iNOS antibodies. The expression of HO-1 in rat liver increased at 72 hours of reperfusion groups after 3 and 10 cycles of remote IP, compared with normal control groups. The expression of HSP70 in rat liver increased at 6 hours of reperfusion groups after 3 cycles of remote IP, compared with normal control groups. The expression of HSP70 in rat liver increased at 0 hour of reperfusion groups after 10 cycles of remote IP, compared with normal control groups and decreased at 24 and 72 hours of reperfusion groups. The expression of iNOS in rat liver increased at 24 hours of reperfusion groups, but decreased at 72 hours of reperfusion groups after 3 and 10 cycles of remote IP, compared with normal control groups. In summary, these results showed that at early phase of reperfusion after remote IP, HSP70 expression was increased in rat liver. However, at 72 hrs of reperfusion after remote IP, HO-1 expression was increased and iNOS expression was decreased in rat liver.