Jiang J K, Chiu J H, Yu I T, Lin J K
Department of Surgery, Veterans General Hospital-Taipei, Taiwan, Republic of China.
Life Sci. 2000 May 5;66(24):2323-35. doi: 10.1016/s0024-3205(00)00563-4.
Rutaecarpine, a compound extracted from the Chinese medicinal herb Evodia rutaecarpa, has been shown to possess relaxing action on vascular smooth muscle from rat thoracic aorta. The internal anal sphincter is a specialized smooth muscle regulating important anorectal physiology. To investigate the effect and underlying mechanisms of rutaecarpine on internal anal sphincter, muscle strips from rabbit internal anal sphincter were used. The results showed that rutaecarpine (1 x 10(-10) M to 1 x 10(-4) M) produced a concentration-dependent muscular relaxation effect in our preparations, which were precontracted with acetylcholine. This muscular relaxation effect was not affected by treatment with L-N(G)-nitro-arginine methyl ester (a nitric oxide synthase inhibitor), methylene blue (a guanylate cyclase inhibitor), N-ethylmaleimide (an adenylate cyclase inhibitor), or by removal of the mucosa and submucosa tissue. Pretreatment with nifedipine (a calcium channel blocker) or extracellular Ca+2 removal by ethylenediaminetetraacetic acid (EDTA) greatly attenuated the relaxation effect, suggesting that calcium ion might be involved. In experiments using strips from human internal anal sphincter, an even more prominent relaxation effect was shown. It is thus concluded that rutaecarpine caused relaxation on internal anal sphincter from rabbits and human subjects. The relaxation action was not related to NO-cGMP pathway, instead calcium ion might play an important role and shed insight into clinical implications for those anorectal disorders with hyperactive anal tone.
吴茱萸碱是从中药吴茱萸中提取的一种化合物，已被证明对大鼠胸主动脉血管平滑肌具有舒张作用。肛门内括约肌是一种调节重要肛肠生理功能的特殊平滑肌。为了研究吴茱萸碱对肛门内括约肌的作用及其潜在机制，采用了兔肛门内括约肌肌条。结果表明，在我们用乙酰胆碱预收缩的制剂中，吴茱萸碱（1×10⁻¹⁰ M至1×10⁻⁴ M）产生了浓度依赖性的肌肉舒张效应。这种肌肉舒张效应不受L-N（G）-硝基精氨酸甲酯（一种一氧化氮合酶抑制剂）、亚甲蓝（一种鸟苷酸环化酶抑制剂）、N-乙基马来酰亚胺（一种腺苷酸环化酶抑制剂）处理的影响，也不受去除黏膜和黏膜下组织的影响。用硝苯地平（一种钙通道阻滞剂）预处理或用乙二胺四乙酸（EDTA）去除细胞外Ca²⁺大大减弱了舒张效应，表明钙离子可能参与其中。在使用人肛门内括约肌肌条的实验中，显示出更显著的舒张效应。因此得出结论，吴茱萸碱可使兔和人肛门内括约肌舒张。这种舒张作用与NO-cGMP途径无关，相反，钙离子可能起重要作用，并为那些肛门张力亢进的肛肠疾病的临床意义提供了见解。
