Emulsified Isoflurane Preconditioning Reduces Lung Injury Induced By Hepatic Ischemia/Reperfusion in Rats

Objective: To investigate whether emulsified isoflurane preconditioning could reduce lung injury induced by hepatic I/R in rats and its mechanism. Materials and methods: 32 pentobarbital-anesthetized Sprague-Dawley rats were equally randomized into four groups: laparotomy group (Sham group), hepatic I/R and normal saline infusion group (I/R+S group), I/R and lipid vehicle infusion (I/R+V group), or I/R and 8% emulsified isoflurane infusion (I/R+E group) at the rate of 8 ml·kg(-1)·h(-1) for 30 min. Blood supply of the hepatic artery and portal vein to the left and the median liver lobes was occluded for 90 min after 30-min washout time. Reperfusion was allowed to proceed for 4 h before sacrifice of the animals. Lung injury was observed histologically. Neutrophil infiltration and TNF-α concentration in serum and lung were measured. Changes of wet-to-dry weight ratios in lung tissue, ICAM-1 expression and NF-κB activity in lung after hepatic I/R were determined. Results: Compared with I/R+S or I/R+V group, emulsified isoflurane preconditioning reduced hepatic I/R-induced lung histologic injury and inhibited the increase of myeloperoxidase (MPO) activity in the lung tissue markedly (5.5±1.37 and 5.22±1.33 vs 3.81±1.62 U/g, P<0.05). In addition, both serum and lung tissue TNF-α levels were reduced in I/R+E group (104.58±31.40 and 94.60±22.23 vs 72.44±17.28 pg/ml, P<0.05; 393.51±88.22 and 405.46±102.87 vs 292.62±74.56 pg/ml, P<0.01). Emulsified isoflurane preconditioning also inhibited the increase of ICAM-1 expression (0.79±0.17 and 0.84±0.24 vs 0.62±0.21, P<0.05) and NF-κB translocation (4.93±0.48 and 4.76±0.57 vs 4.01±0.86, P<0.05) in the lung tissue markedly. Conclusions: Emulsified isoflurane preconditioning markedly attenuated hepatic I/R-induced lung injury in rats, which may be hopefully applied to the clinical treatment of organ injury caused by hepatic surgery, transplantation or hemorrhagic shock.