三七总皂苷对大鼠左心室构型重建的影响

Effect of Total Saponins of Panax notoginseng on Left Ventricular Remodeling in Rats Induced by Isoproterenol

目的探讨三七总皂苷(total saponins ofPanaxnotoginseng,PNS)对大鼠左室重构中一氧化氮(NO)和环磷酸鸟苷(cGMP)含量的影响及其相关机制。方法异丙肾上腺素(isoproterenol,ISO)5 mg.kg-1.d-1,sc,连续7 d,建立大鼠心肌肥厚模型。造模第二天开始大鼠腹腔注射PNS 25和50 mg.kg-1.d-1,连续14 d,测定心脏重量参数;分光光度法检测左心室心肌组织中NO含量和一氧化氮合酶(NOS)活力;放免分析法检测左心室心肌组织中环磷酸鸟苷(cGMP)和环磷酸腺苷(cAMP)含量。结果ISO模型组大鼠心脏重量参数明显增大;左心室诱生型NOS(iNOS)活力和cAMP含量显著升高;NO、cGMP含量和结构型NOS(cNOS)活力显著降低。PNS能明显提高心肌组织NO水平、cNOS活力和cGMP的含量;降低iNOS活力和cAMP含量;减轻心脏重量;抑制左室重构。结论PNS改善大鼠左心室构型重建的作用与其提高NO和cGMP含量有关。

OBJECTIVE To investigate the effects of total saponins of panax notoginseng （PNS） on the contents of nitric oxide （NO） and cyclic guanosine monophosphate （eGMP） in left ventrieular remodeling of rats and to explore its mechanism. METHODS Myocardial hypertrophy model of rats were induced by subcutaneous injection of ISO （5 mg · kg^-1 · d^ -1 ） for 7 d. From second day, the rats were administered（ip） with PNS 25 or 50 mg· kg^-1 · d^-1 ,for 14 d,the control and ISO model groups were received saline injection. Then,the myocardial indexes were measured; the content of cyclic adenosine monophosphate（cAMP） and cyclic guanosine monophosphate （eGMP）in left ventricle; the level of nitric oxide （NO） and nitric oxide synthase （NOS） activity in left ventricle were determined by speetrophotemetry and radioimmunoassay, respectively. RESULTS In ISO model group, the myocardial indexes, the content of cAMP and inducible nitric oxide synthase （iNOS） activity in left ventricle markedly increased;the constitutive nitric oxide synthase （eNOS） activity, the contents of NO and eGMP in left ventricle decreased. Treatment with PNS significantly reduced the myocardial indexes,decreased the cAMP content and iNOS activity; increased eNOS activity and the content of NO and cGMP; lessen heart weight; ihhibited left ventrieular remodeling. CONCLUSION PNS was shown improvment for left ventrieular remodeling induced by ISO in rats and its mechanism may be related to the elevate the contents of NO and cGMP.