Effect of sevoflurane pretreatment on expression of tight junction protein in the lung following ischemiareperfusion injury in rats

Objective To investigate the effect of sevoflurane pretreatment on the expression of tight junction protein Occludin and ZO-1 in the lung following ischemia-reperfusion (I/R) injury in rats. Methods Ninty-six adult male Wistar rats weighing 250-350 g were randomly divided into 4 groups ( n = 24 each): group Ⅰ sham operation (group S);group Ⅱ I/R; group Ⅲ sevoflurane (group Sevo) and group Ⅳ Sevo + I/R. The animals were anesthetized, tracheostomized and mechanically ventilated. Right femoral vein and left carotid artery were cannulated for BP monitoring, blood sampling and drug and fluid administration. Lung I/R was induced by clamping left pulmonary hilum for 45 min followed by 120 min reperfusion in group Ⅱ and Ⅳ. In group Ⅲ the animals inhaled 2.2 % sevoflurane for 30 min. In group Ⅳ the animals inhaled 2.2 % sevoflurane for 30 min before lung ischemia. Six animals were killed at the end of 45 min ischemia (T1), and 60 and 120 min of reperfusion (T2, T3 ). The lungs were immediately removed for determination of W/D lung weight ratio and the expression of Occludin and ZO-1 protein (by Western blot). Tissues of lung were obtained for observation of histopathology with light microscope. Lung permeability index (LPI) was calculated. Another 6 animals were killed at 120 min of reperfusion for lung lavage. Results I/R significantly increased W/D ratio and LPI and significantly reduced Occludin and ZO-1 protein expression in the lung tissue as compared with group C and Sev. Sevoflurane pretreatment significantly attenuated the I/R-induced changes. The pathological damage to the lung tissue was significantly less in group SP than in I/R. Conclusion Sevoflurane pretreatment may protect the lungs from I/R injury by up-regulating the expression of Occludin and ZO-1. Key words: Anesthetics,inhalation; Reperfusion injury; Lung; Tight junctions