大豆蛋白酶抑制剂对内毒素致大鼠急性肺损伤的实验研究

目的：研究大豆蛋白酶抑制剂对内毒素致大鼠急性肺损伤的防治作用。方法：SD雄性大鼠50只，分为假手术组，模型组，阳性药苯甲磺酰氟(PMSF)组，大豆蛋白酶抑制剂高、中剂量组共5组，每组10只。除假手术组外其余各组大鼠气管内注入内毒素(6 mg·kg^-1)，假手术组大鼠气管内注入等量的生理盐水。造模后第1天腹腔注射治疗药物，大豆蛋白酶抑制剂(SBTI)高、中剂量组分别150，100 mg·kg^-1·d^-1。阳性药组大鼠给与等体积的苯甲磺酰氟50 mg·kg^-1·d^-1；假手术组和模型组大鼠腹腔注射等量的生理盐水。造模后第7天取材，测定肺系数、肺通透指数、肺泡灌洗液中细胞计数和中性粒细胞百分比、弹性蛋白酶样活性，肺组织NF-κB和IκBα的活性测定，HE染色进行病理学观察。结果：PMSF和SBTI均能降低急性肺损伤大鼠肺系数、肺通透指数，降低肺泡灌洗液中的细胞总数、活化中性粒细胞百分比和弹性蛋白酶样活性。其中以阳性药组和SBTI高剂量组疗效较显著，阳性药疗效优于SBTI高剂量组。SBTI组大鼠肺组织核蛋白中NF-κB p65的含量明显降低(P<0.01)，SBTI组大鼠肺组织胞浆蛋白中IκBα的含量明显升高(P<0.05)。结论：大豆蛋白酶抑制剂显著降低肺组织的炎症反应，减轻肺组织损伤，对内毒素致大鼠肺损伤具有一定的保护作用。

Experimental study on effect and mechanism of soybean protease inhibitor on endotoxin-induced acute lung injury

OBJECTIVE: To study the protective effect of soybean protease inhibitor on LPS-induced lung injury in rats. METHOD: Fifty male SD rats were randomly divided in five groups, 10 rats in each group as sham-operation group, model control group, positive medicine group, and high, moderate SBTI groups. Except the sham-group, other groups were induced by intratracheal instillation of LPS with a dose of 6 mg x kg(-1). All rats were given drug throughout intraperitoneal injection except the model controlled group, the positive medicine group was given PMSF with a dose of 50 mg x kg(-1), the high dose group of SBTI was given SBTI with a dose of 100 mg x kg(-1), a dose of the moderate group is 50 mg x kg(-1). We examined all rats in seven days. Index exam: cell quantity, activity of neutrophilic granulocyte released elastic protease proteins in BALF, histopathological examination and so on. RESULT: Soybean protease inhibitor can level down the level of total protein, cell quantity, PMN percent, activity of neutrophilic granulocyte in BALF. SBTI level down the content of NF-kappa B in nucleoprotein, while increase the content of I kappa B alpha in plasmoprotein. CONCLUSION: SBTI is useful in protecting experimental pulmonary injury induced by LPS in rats.