Characterization of a novel tetrandrine-induced contraction in rat tail artery  

粉防己碱诱发大鼠尾动脉收缩的新特性(英文)

作　　者：AchikeFI KwanCy 

机构地区：[1]ClinicalSciencesSection,InternationalMediacalUniversity,KualaLumpur,Malaysia [2]DepartmentofMedicine,FacultyofHealthSciences,McMasterUniversity,Hamilton,Ontario,Canada

出　　处：《Acta Pharmacologica Sinica》2002年第8期698-704,共7页中国药理学报（英文版）

摘　　要：AIM: In an attempt to pharmacologically characterize the Chinese antihypertensive drug, tetrandrine, we observed in rat-tail arteries, an unusual contraction in tissues that were stimulated with high [KCl] and not those stimulated with phenylephrine. The characteristics of this contraction were studied. METHODS: Segments of perfused ventral rat-tail arteries (RTA) were contracted with a depolarizing concentration (120 mmol/L) of KCl or with phenylephrine (3.0 micromol/L). At peak contraction, they were exposed to tetrandrine (40 micromol/L), which caused marked relaxation in each case. Washing the RTA led to an unusual, slowly-declining contraction, hereafter referred to as tetrandrine-induced contraction (TIC) which was also observed when the tissues were exposed to 80 micromol/L, but not 10 micromol/L or 20 micromol/L of tetrandrine. RESULTS: Pretreatment with phentolamine (non-selective alpha-adrenoceptor antagonist), prazosin (selective alpha1-adrenoceptor antagonist) or 6-hydroxydopamine (for denervation), but not rauwolscine or atropine abolished the TIC. Treatment with ouabain (Na+/K+-ATPase inhibitor) did not sustain the contraction. Changing the depolarizing concentrations of KCl to 80 mmol/L or 100 mmol/L did not alter the TIC, but at 60 mmol/L, it was abolished. CONCLUSION: The data show that tetrandrine induces a K+-dependent contraction of the RTA through a neuronal mechanism involving alpha1-adrenoceptors. It is speculated that this contraction may be a factor in the reported absence of postural hypotension in the clinical use of tetrandrine.瞄准：在一次尝试到 pharmacologically 描绘中国反高血压的药， tetrandrine，我们在没毛的马尾巴观察了动脉，在高被刺激与的纸巾的不平常的收缩[KCl ] 并且不，那些与 phenylephrine 刺激了。这收缩的特征被学习。方法：酒的腹的没毛的马尾巴动脉(RTA ) 的片断与 KCl 的动摇集中(120 mmol/L ) 或与 phenylephrine (3.0 micromol/L ) 被收缩。在山峰收缩，他们暴露于 tetrandrine (40 micromol/L ) ，它在每种情况中引起了显著松驰。洗 RTA 导致了不平常的、慢慢地衰退的收缩，当纸巾暴露于 80 micromol/L 或 tetrandrine 的 20 micromol/L 时，此后指了也被观察的同样导致 tetrandrine 的收缩(TIC ) 。结果：有 phentolamine (非选择的 alpha-adrenoceptor 对手) 的预告的处理， prazosin (选择 alpha1-adrenoceptor 对手) 或 6-hydroxydopamine (为 denervation ) ，然而并非 rauwolscine 或颠茄碱废除了 TIC。有 ouabain (Na+/K+-ATPase 禁止者) 的处理没支撑收缩。把 KCl 的动摇集中改变到 80 mmol/L 或 100 mmol/L 没改变 TIC，但是在 60 mmol/L，它被废除。结论：tetrandrine 导致的数据表演通过包含 alpha1-adrenoceptors 的 neuronal 机制的 RTA 的 K+ 依赖的收缩。这收缩可以是在在 tetrandrine 的临床的使用的姿势的低血压的报导缺席的一个因素，这被推测。

关 键 词：BENZYLISOQUINOLINES ALKALOIDS Animals ARTERIES Male Muscle Contraction Muscle  Smooth  Vascular PHENYLEPHRINE Potassium Chloride RATS Rats  Sprague-Dawley Tail 

分 类 号：R971.1[医药卫生—药品]