苦丁茶总皂苷对大鼠胸主动脉的舒张作用及其机制初探

目的研究苦丁茶皂苷对大鼠胸主动脉的作用及其机制。方法分别以硝基精氨酸、吲哚美辛及硝基精氨酸与吲哚美辛共同预处理胸主动脉．并测定一氧化氮合成酶（NOS）。结果苦丁茶总皂苷在较高浓度时（高于2mg／mL时）对大鼠胸主动脉有明显的舒张作用，与去内皮组比较，差异具有统计学意义（P〈0．01）。经硝基精氨酸预处理后，苦丁茶总皂苷的舒张作用与空白组比较明显减弱，差异具有统计学意义（P〈0．01）；在经吲哚美辛预处理胸主动脉后，其舒张效应略有减弱，但差异元统计学意义（p〉0.05），若以硝基精氨酸及吲哚美辛共同处理后，舒张作用明显减弱。差异具有统计学意义（P〈0．01），但仍有较弱的舒张作用。酶法测定表明苦丁茶总皂苷可提高胸主动脉中NOS的活性，与空白组比较差异具有统计学意义（P〈0．01）。结论苦丁茶总皂苷具有舒张大鼠胸主动脉的作用，此作用呈内皮依赖性；苦丁茶总皂苷的舒张作用主要与一氧化氮有关。对前列环素的影响不明显。其机制可能是通过提高NOS的活性及促进一氧化氮释放引起的。

Effect and mechanism of total saponins of Ilex kudingcha C.J.Tseng on relaxation 0f thoratic aorta in rats

Objective To investigate the effect of total saponins of Ilex kudingcha C.J Tseng （TSIK）on the thoratic aorta in rats and its primary mechanism. Methods The thoratic aorta of rats was pretreated with L-Nitroarginine and indometacin respectively and the effect of TSIK on the activity of nitric oxide synthetase （NOS） in rat thoratic aorta was detected. Result Compared with endothelium dependent manner, TSIK with the concentration above 2 mg/mL had an obvious effect on the relaxation of rat thoratic aorta （P 〈0.01）; Compared with the control group after pretreated with L-Nitroarginine, the effect of TSIK was weakened （P〈 0.01）, and after pretreated with indometacin, the effect was lightly weakened （P〉0.05） and after pretreated with both L-Nitroarginine and indometacin, the effect was weakened obviously （P〈 0.01）. TSIK enhanced the activity of NOS in rat thoratic aorta with enzyme assay. Conclusion TSIK have an effect tO relax thoratic aorta in endothelium dependent manner, which is probably mediated by enhancing the activity of NOS and promoting the release of nitric oxides.