【摘要】 目的　观察淫羊藿苷 (ICA)对家兔阴茎海绵体平滑肌的舒张效应及机制。方法　采用离体平滑肌张力记录法。结果　①淫羊藿苷、西地那非 (sildenafil,Sil)、罂粟碱 (Pap)及氨力农 (amrinone ,Amr)均可浓度依赖性地引起舒张效应 ,EC50 分别为 0 2 ,11 2 ,31 6和 5 0 1μmol/L。②NO合酶抑制剂N 硝基左旋精氨酸甲酯 (L NAME ) 5μmol/L可将ICA引起的最大舒张效应由 6 0 %降低到 9% ,而NO前体左旋精氨酸 (L Arginine) 2 0 μmol/L ,可部分恢复ICA的最大舒张效应到 4 0 % (P <0 0 5 )。③ICA (1,10 μmol/L)增强Ach引起的舒张效应 ,最大效应由 6 0 %分别升高到 6 7%和 80 % (P <0 0 5 )。④ICA (3,10 μmol/L)能使高K+ (2 0～ 12 0mmol/L)去极化引起的最大收缩反应分别降低到 88%和 81% (P <0 0 5 )。⑤在经 1μmol/L阿托品和 5 μmol/L胍乙啶预先处理的标本上 ,电场刺激可以引起海绵体平滑肌频率依赖性的舒张效应。ICA (1、 10 μmol/L)能增强电场刺激引起的舒张效应 ,最大效应由对照水平的4 1%分别升高到 5 9%和 6 3% (P <0 0 5 )。结论　ICA可以直接舒张阴茎海绵体平滑肌 ,其壮阳作用机制与影响NO cGMP信号通路有关。更多还原

【Abstract】 Objective To investigate the relaxant effects of icariin on the rabbit corpus cavernosum. Methods The changes of tension of isolated smooth muscle strips were recorded. Results (1) Icariin (ICA), sildenafil (Sil), papaverine (Pap) a nd amrinone (Amr) could concentration-dependently relax the smooth muscle of co rpus cavernosum, and their EC 50 values were 0.2, 11.2 , 31.6 , and 50. 1 μmol/L respectively; (2) L-NAME (5 μmol/L) could significantly attenuat e the relaxation of ICA from maximum 60 % to 9 %. L-Arginine (20 μmol/L) could only partly recover the maximum effects of ICA to 40 % (P<0.05); (3) ICA (3, 10 μmol/L) could decrease the contraction induced by extracellular high K+ depolarization, with maximum response from 100 % to 88 % and 81% respectively (P<0.05); (4) Acet ylcholine (Ach)-induced relaxations were enhanced by ICA (1, 10 μmol/L) with m aximum response from 60 % to 67 % and 80 % respectively (P<0.05); (5) On th e specimen pretreated with atropine 1 μmol/L and guanethidine 5 μmol/L, electr ical field stimulation evoked frequency-dependent relaxation, and ICA (1, 10 μ mol/L) could enhance the response with maximum relaxation from 41 % (control) to 59 % and 63 % respectively (P<0.05). Conclusion ICA could relax the smooth muscle of rabbit corpus c avernosum directly and its aphrodisiac effect is involved in the NO-cGMP signal pathway.更多还原