黄芩甙对油酸致急性呼吸窘迫综合征大鼠肺损伤的干预作用

Effects of baicalin on pulmonary functions of acute respiratory distress syndrome induced by oleic acid in rats

目的 探讨黄芩甙对油酸所致急性呼吸窘迫综合征（ARDS）大鼠肺损伤的干预作用.方法 将健康成年雄性SD大鼠随机分为对照组、ARDS模型组和黄芩甙低剂量组（150 mg/kg）、黄芩甙中剂量组（300 mg/kg）、黄芩甙高剂量组（450 mg/kg）,经股静脉注射油酸（0.12 ml/kg）复制ARDS模型,黄芩甙各剂量组同时腹腔注射黄芩甙溶液;在注射油酸后10 min及1、2、6 h,分别插管至颈动脉采集动脉血测血氧分压、采用酶联免疫吸附（ELISA）法对肺组织匀浆进行髓过氧化物酶（MPO）定量检测,并进行组织病理学检查.结果 模型组大鼠在注射油酸后10 min,动脉氧分压和氧合指数开始下降,氧合指数最低值平均为190 mm Hg（1 mm Hg=0.133 kPa）,达到了ARDS的诊断标准（＜200mm Hg）;黄芩甙低剂量组和中剂量组的氧分压和氧合指数也有下降,氧分压最低值分别平均为54.9mm Hg和65.3 mm Hg,与模型组相应时间点比较差异有统计学意义（P＜0.05）;黄芩甙高剂量组的氧分压在10 min时明显下降,均值与模型组比较差异有统计学意义（46.8 mm Hg比66.7 mm Hg,P＜0.05）,之后略有升高,但与模型组相应时间点比较差异无统计学意义（P＞0.05）.模型组和黄芩甙中剂量组大鼠肺组织MPO浓度均高于对照组,但黄芩甙中剂量组在10 min及1、2 h时均低于模型组.肺组织病理检查结果显示,黄芩甙中剂量组肺损伤较模型组轻.结论 适宜剂量的黄芩甙可以改善油酸所致大鼠ARDS的缺氧状态,这一作用可能与抑制MPO活性有关.

Objective To investigate the effect of baicalin on pulmonary functions and its mechanism during the development of acute respiratory distress syndrome （ARDS） induced by oleic acid （OA） in rats. Methods Rats were randomized into 5 groups： control, ARDS （OA induction, 0.12 mg/kg）,baicalin-treated group （ 150 mg/kg）, baicalin-treated group （300 mg/kg） and baicalin-treated group （450mg/kg）. The blood samples and lung tissue were collected at 10 min, 1, 2 and 6 h after OA injection. The lung concentration of myeloperoxidase （MPO） was detected by an ELISA （enzyme-linked immunosorbent assay） kit. Meanwhile, blood gas analysis and pulmonary pathological examination were also performed. Results The level of arterial oxygen partial pressure and oxygenation index decreased （P ＜0. 01vs. control） and oxygenation index （ 190 mm Hg, 1 mm Hg =0. 133 kPa） reached the diagnostic standard of ARDS at 2 h in ARDS group. In baicalin-treated group （ 150 mg/kg and 300 mg/kg）, the level of arterial oxygen partial pressure and oxygenation index increased versus the ARDS group. In baicalin-treated group （450 mg/kg）, the level of arterial oxygen partial pressure was undifferentiated at 1,2 and 6 h （P ＞0. 05）and decreased at 10 min （46. 8 mm Hg, P ＜0. 05 ） versus the ARDS group. The level of MPO increased in baicalin-treated （300 mg/kg） and ARDS groups. Compared with the ARDS group, the level of MPO decreased significantly in baicalin-treated group （300 mg/kg） at 10 min, 1 and 2 h. Meanwhile, the pulmonary pathological damage improved in baicalin-treated group （300 mg/kg）. Conclusion An appropriate dose of baicalin may improve hypoxemia of ARDS induced by OA in rats. It may be due to the inhibition of MPO activity.