Effects of propofol on lung injury and PI3K/Akt pathway in rats after liver ischemia and reperfusion

AIM:To study the effect of propofol on phosphatidylinositol-3 kinase/protein kinase B(PI3K/Akt) signaling pathway in the model of rat lung injury after hepatic ischemia and reperfusion(IR).METHODS:Sixty-six SD rats were randomly divided into 4 groups:sham operation group(n=6),IR group(n=24),propofol group(n=24) and propofol+wortmannin group(n=12).The rats in IR group and propofol group were further divided into 4 subgroups according to the time points of 1 h,3 h,6 h and 12 h after reperfusion.The rats in propofol+wortmannin group were also divided into 2 subgroups according to the time points of 3 h and 6 h after reperfusion.The rats in sham group were only dissected porta without ligation.The ligation of hepatic pedicle in the rats in IR group was performed to induce liver ischemia for 30 min and then reperfusion was conduced.The rats in propofol group were given slow injection of propofol(20 mg/kg) from the caudal vein 10 min before ischemia,and then propofol was continuously pumped at dose of 20 mg·kg-1·h-1 until rats' death.Other procedures were the same as the rats in IR group.The rats in propofol+wortmannin group were injected with wortmannin,a blocker of PI3K,at dose of 15 μg/kg before ischemia,and also given the injection of propofol as the rats in propofol group.The lung tissues of the rats were collected at the time points of 1 h,3 h,6 h and 12 h after reperfusion.The protein levels of total Akt(t-Akt),phosphorylated Akt(p-Akt) and Bcl-2 in the lung tissues were detected by Western blotting.The apoptotic rate was analyzed by flow cytometry with annexin V-FITC/PI staining.RESULTS:Compared with sham group,the protein levels of p-Akt and Bcl-2,and the cell apoptotic rate in the lung tissues in IR group,propofol group and propofol+wortmannin group increased.Compared with IR group,the protein levels of p-Akt and Bcl-2 increased,and cell apoptotic rate of the lung tissues decreased in propofol group.Compared with propofol group,the protein levels of p-Akt and Bcl-2 decreased,and cell apoptotic rate in the lung tissues increased in propofol+wortmannin group.CONCLUSION:Propofol reduces the lung injury in rats induced by liver ischemia and reperfusion,and its mechanism may be involved in PI3K/Akt signaling pathway.