低分子肝素联合乌司他丁治疗急性百草枯中毒大鼠肺纤维化的实验研究

目的探讨低分子肝素联合乌司他丁减轻急性百草枯（PQ）中毒大鼠肺纤维化的可能作用机制。方法55只雄性SD大鼠，随机分成正常对照组（A组）、模型组（B组）、治疗组（C组）；B、C组禁食1h后经口一次灌胃百草枯75mg／kg制作PQ大鼠肺纤维化模型，A组经口一次性注人等量生理盐水；c组造模后皮下注射低分子肝素钠1000U／d，同时腹腔注射乌司他丁10万U，共14d，A、B组给予0．2ml／d生理盐水皮下注射。分别于造模后1、3、7、14、28d测定血清转化生长因子β1（TGFβ1）、基质金属蛋白酶9（MMP-9）含量；并取肺组织做HE染色。结果与A组比较，B组血清TGF-β1第3天始明显升高（P〈0．01），血清MMP-9于第7天逐渐上升（P〈0．05），第28天明显升高（P〈0．01）；与B组各相同时间点比较，C组MMP-9水平下降，至第7天差异有统计学意义（P〈0．05），第28天出现明显下降（P〈0．01）；而血清TGF．131在第14天开始出现明显下降（P〈0．01）。B组于造模后早期即出现肺泡壁增厚，炎症细胞浸润明显，毛细血管充血、水肿等，14d肉眼可见肺表面溃疡形成，镜下可见肺泡间隔成纤维母细胞、肌纤维细胞增生，肺泡塌陷；C组于14d时镜下可见有肺泡壁毛细血管充血，炎性细胞浸润较B组轻，肺纤维化程度也有所减轻。结论低分子肝素联合乌司他丁可减少MMP-9的合成，从而减轻大鼠纤维化程度，其途径可能通过减少TGF．Bl的合成。

Therapeutic effects of combined LMWH and UTI on pulmonary fibrosis induced by acute Paraquat poisoning in rats

Objective To investigate the preventive effects of low molecular weight heparin （LMWH） combined with ulinastatin （UTI） on the acute Paraquat poisoning in rats with pulmonary fibrosis. Methods Fifty five SD rats were divided into control group （group A）, pmonary fibrosis group （group B） and prevention group （group C）. Pulmonary fibrosis （group B and C） was induced by feeding the rats with Paraquat after fasting for one hour （75 mg/kg）, and group A received normal saline. Then the rats in group C received low molecular weight heparin （1 000 U/d, subcutaneous injection） and UTI （105 U, peritoneal injection） for 14 days. Group A and B received normal saline （0.2 ml/d）. Five rats in each group were killed on the lth, 3th, 7th, 14th and 28th days, respectively. Specimens from lung tissue and serum were collected. HE staining of lung tissues was prepared and the serum levels of transforming growth factor β1 （TGF-β1） and matrix metalloproteinase 9 （MMP-9） contents were measured. Results Serum level of TGF-β1 in group B was significantly increased at day-3 （P 〈0.01 ）, serum MMP-9 was gradually increased in the first 7 days （P〈0.05）, and was significantly higher （P〈0.01） at day-28. Level of MMP-9 in group C at the 7th day was decreased compared with group B （P〈0.05）, and the level was significantly difference at day-28 （P〈0.01）. Level of TGF- β1 in group C at day-14 was decreased and the value was significantly different from group B at the day-14 （P〈0.01）. Alveolar wall thickness was increased in the B group during the early phase after making a model. Infiltration of inflammatory cells, capillaries congestive, and edema were obvious at day-14. Lung surface ulcer was found, and alveolar interval into fiber mother cells, Muscle fiber cell hyperplasia and alveolar eollapsion could be seen under electron microscope. When the C group has alveolar wall capillaries congestive, inflammatory sexual cell infiltration more model group light, lung fiber of degree also more by reduce. Conclusion Low molecular weight heparin combined with ulinastatin may reduce TGF-β1 and MMP-9,thereby reducing fibrosis in rats.