β3肾上腺素受体介导多巴胺对大鼠远端结肠运动的抑制作用  

β3-Adrenoceptors Participate the Inhibition of Dopamine on Rat Distal Colon Motility

作　　者：郭华[1] 徐敬东[1] 李利生[1] 张晓慧[1] 朱进霞[1] 

机构地区：[1]首都医科大学生理教研室,北京100069

出　　处：《中国实验动物学报》2009年第4期258-260,共3页Acta Laboratorium Animalis Scientia Sinica

基　　金：国家自然科学基金项目(编号:30770799);北京市教委重点项目(编号:KZ200910025003)

摘　　要：目的研究多巴胺(DA)对大鼠结肠运动影响的机制。方法采用离体组织灌流方法记录大鼠远端结肠自发性节律运动,观察DA的作用以及阻断剂的影响,再用反转录实时多聚酶链反应(real time RT-PCR)检测受体基因的表达。结果DA(≥1.0×10-5mol/L)对结肠远端(紧接肛门淋巴结近端)离体纵行肌条(2.0 mm×10 mm)的运动具有抑制作用,多巴胺受体阻断剂(D1受体阻断剂SCH23390,1.0×10-7mol/L,D2受体阻断剂Sulpide,1.0×10-7mol/L)不能阻断多巴胺的抑制效应,但加入β3受体抑制剂cyanopindolol(7.5×10-7mol/L),DA的抑制作用显著减弱。real time RT-PCR检测发现β1、β2、β3受体mRNA在远端结肠均有表达。结论DA可通过β3受体发挥对远端结肠运动的抑制作用。Objective To study the mechanism underlying inhibitory effect of dopamine（DA） on the colon motility in the rat.Methods By in vitro tissue perfusion technique,the effects of DA and its antagonist on the autonomic rhythm of motility of rat distal colon were investigated.Then,the receptor expression was measured by real-time RT PCR.Results DA（≥1.0×10^（-5） mol/L） markedly inhibited the motility of longitudinal muscle strips（2.0×10 mm） of the rat distal colon（2.5 cm away to anus）.Both D1 receptor antagonist SCH23390（1.0×10^（-7） mol/L） and D2 receptor antagonist sulpide（1.0×10^（-7） mol/L） failed to block the inhibitory effect of DA on the colonic motility.However,the inhibitory effect of DA on the colonic motility was notably suppressed by pretreatment with antagonist of β3-adrenoceptor,cyanopindolol（7.5×10^（-7） mol/L）.Moreover,β1,β2,β3-adrenoceptors mRNAs were all expressed in the rat distal colon.Conclusion Dopamine can inhibit the motility of distal colon,which is mediated by β3-adrenoceptor.

关 键 词：多巴胺 远端结肠 平滑肌运动 Β肾上腺素能受体 大鼠 

分 类 号：R333.3[医药卫生—人体生理学]