| The intestinal ischemia and reperfusion (IIR) can all take place in clinical and various circumstances, and is a pathologic foundation of clinical and a series of disease; Such as the mesenteric arterial embolism, volvulus , bowel obstruction , hemorrhagic shock, seriously many hair wound, abdominal aortic aneu-rysm surgical operation etc. , there would be the IIR in the course of diseases and under medical treatment; In the intestinal ischemia process, IIR can cause the cell dysfunction and dropsy of cell and cell cleft, and cause the cell death at serious hour; The reperfusion have below two beneficial aspects to ischemic tissue : energy supply rectifing and the clearance of the toxic metabolites; So it is the precondition for reperfusion that ischemic tissue recovers from injury; However, the ischemic tissue reperfusion can also cause the serious damage of local tissue, and can cause the harm of the remote organ (the lung, liver and kidney ). It can often cause the complications of acute respiratory distress syndrome , hypotention and liver - kidney function failure etc. , mortality is 44% ~ 89%.Lung injury appear usually first of all, the characteristics of lung injury is noncardiogenic pulmonary edema, increased microvascular permeability and the accumulating of polymorphonuclear neutrophil ( PMN) in lung tissue; Consequently it cause the lung dysfunction or failure in respiring, which turn to worsen the intestinal ischemia damage, at last cause the multiple organ dysfunction syndrome , and endanger the patient life. It is reported that the activating and num-ber increasing of PMN in the lung and other organ may be an important link to cause MODS, Now the mechanism of lung injury induced by IIR suffer the concern , and may involve various inflammatory and vascular activated mediators including the oxygen free radicals, PMN, endothelium factors... etc. ; It's unknown which one is the predominant position in the injury, and it is the hot point of current research; As to protecting of lung injury after IIR rounding the surgical operation and anaesthetizing period is rare report, therefore the further research is necessary.Propofol, the currently available vein anaesthetic agent, has been used in clinical anaesthesia and patient sedation in intensive care unit because its quikly induction and emergency and safety dependable; and as propofol is chemically similar to phenol - based free radical scanvengers such as butylated hydroxytolu-ene ( BHT) and the endogenous antioxidant vitamine E ( VitE) ; So it should be a free radical scanvenger, and its function include to lower the tissue oxygen consumption, direct clearance of free radicals, restraining lipid peroxidation respond and regulating the equilibrium of cell calcium etc. Propofol scanvenge free radical species by a process of hydrogen abstraction, and itself become a phe-noxyl radical. According to current data, it is the main mechanism for antioxida-tion of propofol to restrain lipid peroxidation respond.There are interactiongs between free radicals and calcium overload and be in conjunction with each other; Eriksson etc. the experiment express, at high oxidize respond the propofol can pass to succeed in catching the free radicals, repress oxygen free radicals or restraining the reversibility open of ionic channel protein induced by lipid peroxidation respond, and prevent permeability increasing of mitochondria membrane, mitochondria swell and accumulation of haemo-lytic phosphoric lipid; At low oxidize respond propofol can direct act on the membrane composition, preventing permeability increasing of mitochondria membrane, stabilizing membrane construction, further enhancing antioxidation of propofol .At present, the propofol's anti - oxygenation study is mainly concentrated on the protection of myocardial and nerve cell; there is no reports of its protective effects on lung injury induced by IIR; This study is to observe the influenceof propofol on rat lung injury after IIR and investage the mechanism of lung protection , whi...
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