小檗碱对兔阴茎海绵体的舒张效应及作用机制

Relaxant Effect of Berberine on Isolated Rabbit Corpus Cavernosum

目的 观察小檗碱(berberine, Ber) 对离体兔阴茎海绵体平滑肌条的舒张效应, 探索其作用机制。方法 采用离体平滑肌张力变化记录技术观察Ber对离体兔海绵体肌条的作用。结果 在离体兔阴茎海绵体平滑肌标本上①Ber、西地那非(sildenafil, Sild)、罂粟碱(papaverine, Pap) 及氨力农(amrinone, Amr) 均可浓度依赖性地引起舒张效应, 其作用强度依次为Sild>Ber>Pap>Amr, EC50分别为0 .84, 6 .20, 15. 00 和27. 69μmol/L。②当NO合酶抑制剂L NAME (0. 1 mmol/L) 存在时, Ber的最大舒张效应由100 0 %降低到(84. 0 ±3 .4)%。当同时加入L Ar ginine (1 mmol/L) 时, 可部分对抗L NAME的作用, Ber对海绵体的最大舒张效应可恢复到(96 0 ±4 5)%。③Ber (1, 10μmol/L) 浓度依赖性地增强乙酰胆碱(ACh) 引起的舒张效应, ACh的最大效应分别由(72. 0 ±3 .6)%升高到(81. 0 ±5 .4)% 或(93. 0 ±6 .3)%。④Ber (1, 10μmol/L) 对KCl 去极化引起的收缩反应的作用微弱(P>0 .05)。结论 Ber对兔阴茎海绵体具有浓度依赖性舒张作用, 其机制与影响NO -cGMP信号通路有关。

Objective To study the relaxant effects of berberine (Ber) on rabbit isolated corpus cavernosum.Methods Corpus cavernosum isolated from rabbits was exposed to increasing concentration of Ber and the changes of tension of isolated smooth muscle strips were recorded.Results ①Ber,sildenafil (Sild),papaverine (Pap) and amrinone (Amr) could concentration-dependently relax the smooth muscle of corpus cavernosum and the rank order of potency was: Sild>Ber>Pap>Amr. Their EC_ 50 was 0.84,6.20,15.00 and 27.69 μmol/L respectively.②L-NAME (0.1 mmol/L) could significantly attenuate the relaxation of Ber from maximum 100.0 % to (84.0±3.4) %,while L-arginine (1 mmol/L) almost completely recovered the maximum effects of Ber with maximum effect restoring to (96.0±4.5) %.③acetylcholine (ACh)-induced relaxation was enhanced by Ber (1 and 10μmol/L),with maximum response from (72.0±3.6) % to (81.0± 5.4) % or (93.0± 6.3) % respectively.④Ber (1 and 10μmol/L) had a slight effect on the contraction induced by extracellular high K + depolarization (P>0.05).Conclusion Ber possessed a concentration (1 μmol/L and 0.1 mmol/L)-dependent relaxation in phenylephrine (PE)-precontracted corpus cavernosum and the mechanism of relaxation is attributed to NO-cGMP signal pathway.