Effect of ulinastatin preconditioning on the expression of hemeoxygenase-1 in limb ischemia reperfusion lung injury in rats

To investigate the role of HO-1 in ischemic preconditioning and pharmacological preconditioning by ulinastatin in attenuating remote lung injury in rat model of lower limb ischemia reperfusion. Sixty four male SD rats were randomly divided into four groups: Sham operation group, ischemia and reperfusion group, ischemia preconditioning group (IPR), ulinastatin preconditioning group (UTI). The animals were deeply anesthetized and the lung tissue was removed at the end of the experiment. Lung W/D ratio were measured and the expression of HO-1 was determined by Immunohistochemical staining and western blotting. HO-1 was induced and expressed persistently in 2 and 4 h after ischemic preconditioning and ulinastatin preconditioning (P<0.01), and the expression in 4 h was higher than 2 h in preconditioning groups (P<0.05). The preconditioning also led to diminished lung edema (W/D ratio) (P<0.05 vs I/R), with no differences when compared to the sham group. The induction of HO-1 by ischemic preconditioning and ulinastatin preconditioning played a protective role against remote lung injury in the model of limb injury/reperfusion.   Key words: Heme oxygenase-1, preconditioning, ulinastatin, ischemia/reperfusion.