右美托咪定抑制离体家兔十二指肠平滑肌自发收缩  

Dexmendetomidine decreases spontaneous contraction of duodenal smooth muscle of rabbits in vitro

作　　者：苗穗兵[1] 陈华[2] 崔芳[3] 田思雨[3] 谷硕[3] 关玥[3] 

机构地区：[1]河北医科大学生化教研室 [2]河北省人民医院心脏三科 [3]河北医科大学生理学教研室,河北石家庄050017

出　　处：《中国药理学通报》2016年第8期1101-1104,共4页Chinese Pharmacological Bulletin

基　　金：河北省科技厅课题资助项目(No 152777225)

摘　　要：目的观察右美托咪定对离体家兔十二指肠平滑肌自发收缩的影响,并探讨其机制。方法健康家兔,♂♀不拘,击晕并分离十二指肠,将肠段与张力换能器相连并置于氧饱和的Krebs-Henseleit(K-H)液中。采用BL-420F生物信号采集处理系统记录离体家兔十二指肠平滑肌自发收缩的幅度(amplitude,AM)和频率(frequency,FR)。累加给药法观察不同浓度右美托咪定对离体家兔十二指肠平滑肌自发收缩的影响。K-H液中,预先孵育格列苯脲(glibenclamide,Gli)后再加入右美托咪定,研究其作用机制;无钙K-H中预先加入右美托咪定后再分别加入CaCl_2和雷诺丁(Rynodine),进一步研究其作用机制。结果 1右美托咪定剂量依赖性地抑制离体家兔十二指肠平滑肌自发收缩的幅度(P<0.05,P<0.01),但对频率无影响(P>0.05);2 Gli(P<0.05)可部分阻断右美托咪定对离体家兔十二指肠平滑肌自发收缩的抑制作用;3无钙K-H液中,右美托咪定可分别抑制由CaCl_2(P<0.05)外钙增加和Rynodine(P<0.05)内钙释放所诱发的收缩。结论右美托咪定抑制离体家兔十二指肠平滑肌的自发收缩,其作用可能是通过兴奋ATP敏感性钾通道(K_(ATP))以及同时抑制外钙内流、内钙释放实现的。Aim To observe the influences of dexmendetomidineon the spontaneous contraction of duodenalsmooth muscle of rabbits in vitro and explore the mechanisms.Metliods The rabbits （ male or female ） werestunned and the duodenums were isolated. The samplesof duodenal segments were connected with tensiontransducer, which were then put into oxygen saturationKrebs-Henseleit（ K-H ） solution. The influences of dexmendetomidineon amplitude （ AM ） and frequency（FR） of duodenal smooth muscle were recorded byB L -420F biological signal processing system. The cumulativedosing method was used to observe the differentconcentrations of dexmedetomidine on duodenalsmooth muscle spontaneous contraction. Glibenclamide（Gli） was added to K-H solution before dexmendetomidine.In the calcium-free K-H solution, calciumchlorde and rynodine were added before dexmendetomidine.The mechanisms of dexmendetomidine werestudied. Results ① Dexmendetomidine reduced theamplitude of spontaneous contraction of duodenalsmooth muscle in rabbits in a dose-dependent manner（ P 〈0. 05 or P 〈0. 01）, while the frequency was notobviously influenced （ P 〉0.05 ） ②Gli （ P 〈0.05 ）partly abolished the inhibitory effects of dexmendetomidineon duodenal smooth muscle. （③ Dexmendetomidineinhibited the contraction of duodenum smoothmuscle induced by calcium chlorde （ P 〈 0. 05 ） andrynodine（P 〈0. 05 ） application into calcium-free K-H solution. Conclusion Dexmendetomidine inhibits thespontaneous contraction of duodenal smooth muscle ofrabbits i vitro. The mechanisms may be related to activating ATP sensitive potassium channels, inhibition ofthe extracellular calcium influx via cell membrane andintracellular calcium release via sarcoplasmic reticulumin duodenal smooth muscle.

关 键 词：右美托咪定 十二指肠平滑肌 自发收缩 ATP敏感性钾通道 外钙内流 内钙释放 家兔 

分 类 号：R-332[医药卫生] R348.1