人参二醇组皂苷对感染性休克大鼠血清一氧化氮合酶及一氧化氮的影响

目的观察人参二醇组皂苷（PDS）对感染性休克大鼠血清中一氧化氮合酶（NOS）活性及一氧化氮（NO）含量的影响，探讨其抗感染性休克的作用机制。方法大鼠舌下静脉注射PDS进行预治疗，10rain后注射细菌内毒素（LPS5mg／kg）复制感染性休克模型。实验动物随机分为对照（Control）组；内毒素休克（LPS）组；地塞米松（LPS＋Dex）组；人参二醇组皂苷（LPS＋PDS）组。颈动脉插管记录平均动脉压（MAP）。分别于休克后2h和4h腹主动脉取血，用硝酸还原酶法测定血清中NOS活性和N02^-／NO3^-的含量，间接反映N0的水平。结果注射内毒素后，模型组的MAP迅速下降，在低水平维持，LPS＋Dex组和LPS＋PDS组的MAP未见明显下降，优于模型组（P〈0．01）；注射内毒素2h后模型组的血清NOS和NO明显升高，LPS＋Dex组和LPS＋PDS组NOS活性、NO2^-／NO3^-含量显著低于LPS组（P〈0．05）。结论PDS能够明显改善内毒素休克大鼠的低血压状态，降低NOS活性、NO含量，并对其NO的生成具有抑制作用。

Effects of PDS on serum NOS activity and NO levels of endotoxic shock rats

Objective] To study the effects of PDS on the endotoxic shock rats and its mechanism by analyzing serum NOS activity and NO levels. Methods] PDS was injected into ranine vein and ten minutes later septic shock model was induced by injecting LPS 4 mg/kg. Rats were randomly divided into LPS, LPS+Dex, LPS+PDS and control groups respectively. MAP was measured through carotid arterial cannula and blood was collected through abdominal aorta 2 h and 4 h after shock. NOS activity, content of NO2- /NO3- in serum were assayed by nitrate reductase method to indirectly reflect NO content. Results] MAP of model decreased significantly after injection of ETX and maintained at lower level. While MAP of LPS+Dex, LPS+PDS showed obvious decrease. NOS activity and NO content of model increased significantly 2 h after injection of ETX while NOS activity and content of NO2-/NO3- of LPS+Dex and LPS+PDS groups decreased obviously with compared with LPS group. Conclusion] PDS can improve hypotension in septic shock rats, inhibit NOS activity and reduce NO content by inhibiting its production.