| Acute lung injury (ALI)is a kind of inflammatory syndrome clinicallycharacterized as the increase in blood vessel permeability .It's induced by variousdangerous factors outside pulmonary system with complicated pathogenesis. It mayresult in acute respiratory distress syndrome(ARDS), systemic inflammatory responsesyndrome (SIRS), multiple organ dysfunction syndrome (MODS), or multiple organfailure (MOF) that may contribute to the synthesis of cytokines and other inflammatorymediators. However, the exact of mechanisms of ALI remain unclear. Until now there isno effective therapeutic principles and the mortality reaches as high as 50-70%. Thecauses and development of ALI are much related with the disbalance of the proteaseenzyme and anti-protease enzyme system. Current belief is that anti-protease can preventthe development of ALI successfully. The change of the pathogenesis and development of ALI that is induced byintratracheal instillation of bacterial lipopolysaccharide is the same of those of clinicalARDS . LPS treatment result in neutrophil recruitment associated with acute lunginflammation and injury, then neutrophil produce proteolytic enzymes that specificallydamage ECM components. They are secreted by inflammatory cells and mayconsequently contribute to the lesions of the ECM observed during acute pulmonaryedema. It is reported that SBTI have anti-inflammation, it can especially restrain theactivity of trypsin, and elastase. At present , it have been used in anti-cancer and therapyof AIV, and these is few report in therapy of ALI. In theory, we consider that SBTIprobably has an important foreground in therapy of ALI . Objective: To extract and isolate the component of trypsin inhibitor from soybean;To study the protective effect of SBTI on LPS- induced lung injury in rats, Furthermore,we want to study the mechanism simply .In order to supply the basic theory andexperimental data for prevention and treated of ALI by Traditional Chinese and Westernmedicine combination. Methods: The first part is to establish a effective method of extracting proteaseinhibitor from soybean and exam the specific activity of soybean protease inhibitor. Thecoarse protein of SBTI was extracted by HAc-NaAc buffer solution with certain pH; andthe coarse protein was divided into different molecular weight segments by Millipore;and then the aim protein was deposited by the method of salting-out, and (NH4)2SO4was taken out by dialysis; the molecular weight were examined by SDS-PAGEelectrophoresis; and finally the protein concentration was measured by the method ofBradford; and the inhibiting activity was examined by the reaction mechanism of enzymewith substrate; In the second part , .120 male SD rats, weighting 180±20g, were randomlydevided in six groups. (20 rats in each group) as normal group, sham-operation group,model control group, positive medicine group, and high, moderate SBTI groups.PMSF-treated is the positive controlled group. Except the sham-group, other groups. Arat model of ALI was induced by intratracheal instillation of LPS with a dose of6mg/kg. All rats were given drug throught intraperitoneal injection except the normalgroup and the model controlled group,the positive medicine group was given PMSFwith a dose of 50mg/kg, the high dose group of SBTI was given SBTI with a dose of100mg/kg, a dose of the moderate group is 50mg/kg. we examed all rats in three daysand seven day partly . At first , we mainly study the protective effect of SBTI on LPS-induced lung injury in rats. Including BALF index exam: Cell quantity, Level of totalProtein, Activity of neutrophilic granulocyte released elastic protease proteins in BALF,histopathological examination and so on. Beside we observe the effect of SBTI on NF-κB and IκBαin LPS-induced lung injury of rats , The activity of NF-κB and IκBαinthe protein of pulmonary tissues was studied by means of Western blotting. Result:1. Due to the timeworn equipment, The SBTI which was extracted and isolated was relatively coarse, and establish a effective method of examing the speci...
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