Effects of Tea Polyphenols on Lung Injury Following Intestinal Ischemia/Reperfusion in Rats

Objective To explore the protective effect of tea polyphenols on lung injury after intestinal ischemia/reperfusion(I/R)in rats,and the potential mechanism of which.Methods Thirty two male SD rats were randomly divided into 4 groups(n=8 in each).①Group I/R,in which rats were subjected to 1 hour of occlusion of the superior mesenteric artery(SMA),followed by 2 hours of reperfusion;② Early treatment group(P1),rats were subjected to the same procedure as group I/R with the additional administration of tea polyphenols 10 minutes before ischemia at 10 mg·kg-1 loading dose,followed by continuous infusion at 10 mg·kg-1·h-1;③ Treatment group(P2),rats were subjected identical treatment as group I/R with the administration of tea polyphenols started 10 minutes before reperfusion at 10 mg·kg-1 loading dose,followed by continuous infusion at 10 mg·kg-1·h-1;④Sham-operation group,rats were subjected to laparotomy only,but received normal saline at 10 mL·kg-1·h-1.At the end of reperfusion,all animals were sacrificed.The MPO and TNF-α in plasma and lung tissue was assessed.Pathological sections of lung and empty intestine were made Results MPO and TNF-α in plasma and expression in lung tissue were increased significantly in group I/R.All the increase was less in quantity in the early treatment group of tea polyphenols than those in the other two groups,and there was significant difference in contents and expression in lung between group I/R and group P1(P0.05).Conclusion MPO and TNF-α plays an important role in lung injury after intestinal I/R.The early treatment of tea polyphenols before intestinal I/R may be more beneficial by reducing MPO and TNF-α expression in lung injury.