Heat shock preconditioning reduces the formation of 8-hydroxy-2'-deoxyguanosine and 4-hydroxy-2-nonenal modified proteins in ischemia-reperfused liver of rats

Heat shock preconditioning (HSPC) is a promising strategy for providing ischemic tolerance. The objective of this study is to investigate the effectiveness of HSPC in preventing oxidative damage of cellular proteins and DNA during ischemia-reperfusion of the liver. Male Wistar rats were divided into a heat shock group (group HS) and control (group C). Forty-eight hours prior to ischemia, rats in group HS received HSPC at 42 degrees C for 15 min. All rats received hepatic warm ischemia for 30min and subsequent reperfusion. The formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (HNE) modified proteins in liver tissue, survival rate of the animals, and changes in biochemical and histological parameters were compared between groups. Heat shock protein 72 was produced only in group HS. The 7-day survival of rats was significantly better in group HS (10/10) than in group C (5/10) (p < 0.01). The serum release of alanine aminotransferase (n = 10, p < 0.01) and the concentration of adenosine triphosphate in liver tissue (n = 10, p < 0.01) 40min after reperfusion was significantly better in group HS than in group C. The formation of 8-OHdG in liver tissue measured by high-performance liquid chromatography was suppressed in group HS (p < 0.01). The production of HNE-modified proteins as determined by Western-blot analysis was also decreased in group HS. These results were also confirmed by immunohistochemical analysis. As determined by levels of 8-OHdG and HNE-modified proteins produced during ischemia-reperfusion of the liver, HSPC reduced the oxidative injury of cellular proteins and DNA in the liver tissue.