Expression change of GSH-Px in lung of hepatic ischemia-reperfusion injury rats

Objective To observe the expression change of glutathione peroxidase (GSH-Px) in lung of hepatic ischemia-reperfusion injury (HIRI) rats and explore the role of GSH-Px in protecting lung against peroxide damage by inhibiting oxidative stress. Methods The HIRI rat model was established by clipping the blood vessel of both hepatic right and middle lobes as well as bile duct with non-damage vascular clamp for 30 minutes, discarding the blood vessel clip to retore blood supply.The serum, liver and lung were taken after reperfusion for six hours.The activity of serum alanine aminotransferase (ALT) was detected with rate method.The morphological changes of liver were observed with hematoxylin-eosin staining.The content of malondialdehyde (MDA) in lung tissue was determined with thiobarbituric acid colorimetric method.The content of hydrogen peroxide (H2O2) in lung tissue was determined with molybdate colorimetric method.The activity of GSH-Px was determined with colorimetric method.The expression of GSH-Px mRNA was evaluated by reverse transcription-polymerase chain reaction.The level of GSH-Px protein was estimated by Western blot. Results Compared with the control group, the morphological structure of liver tissue was significantly damaged, the activity of serum ALT, the MDA content and H2O2 content in lung tissue were significantly increased, the activity, mRNA and protein expressions of GSH-Px were also significantly enhanced in HIRI group. Conclusions HIRI causes lung tissue to be in oxidative stress and subjected to peroxide damage.Antioxidant enzyme GSH-Px may play a role in anti-oxidative stress and protect lung against peroxide damage. Key words: Hepatic ischemia-reperfusion injury; Glutathione peroxidase; Malondialdehyde; Hydrogen peroxide; Oxidative stress