5-HT及其阻断剂脑内微注射和微电刺激对家兔胃电活动的影响  

Effects of intracerebral microinjection of 5-hydroxytryptamine and its blocking agents and intracerebral microelectric stimulation on gastric electrical activity in rabbits

作　　者：张慧[1] 欧阳守[1] 黄伟锋[1] 

机构地区：[1]厦门市医药研究所,福建省厦门市361003

出　　处：《世界华人消化杂志》2009年第31期3189-3196,共8页World Chinese Journal of Digestology

基　　金：厦卫科教中医(2006)363号基金资助项目;No.WZK21;厦卫科教中医(2007)480号基金资助项目;No.3502z20077077;福建省科技计划重点项目基金资助项目;No.2009D026~~

摘　　要：目的:观察室旁核及中缝大核微注射5-羟色胺(5-hydroxytryptamine,5-HT)及其各种阻断剂和电刺激对家兔胃电活动的影响,探讨室旁核影响胃肠运动的中枢地位.方法:注射5-HT及其各种阻断剂和电刺激家兔室旁核,然后采用胃浆膜双极4导联同步记录,分析其胃体、胃窦部胃电的平均频率、相位差、负相位比率、波形对应率、幅度等指标,考察室旁核及中缝大核微量注射5-HT及各种阻断剂和电刺激对家兔胃电活动的影响.结果:室旁核注射2μg5-HT后,除胃体3外胃电频率均加快,其中胃体2差异显著(4.44±0.09vs4.24±0.09,P=0.034),再注射5μg丹司琼后胃电频率均减慢,其中胃体2、3差异显著(P=0.032,0.043);室旁核注射2μg5-HT再注射5μg赛庚啶后,胃电频率加快,胃体2差异显著(P=0.044);室旁核电刺激后,除胃体2外胃电频率均减慢,胃体1和胃体3差异显著(P=0.03,0.029);中缝大核注射10μg5-HT后,胃体2胃电频率明显减慢(4.13±0.11vs4.33±0.09,P=0.021),再注射10μg赛庚啶后,胃体2胃电频率则加快(P=0.034);注射10μg5-HT再室旁核电刺激后,除胃体1外胃电频率均减慢,胃窦部位差异显著(3.93±0.14vs4.46±0.14,P=0.006).结论:室旁核微量注射5-HT对胃电活动主要为激动作用,可能是通过5-HT3受体途径发挥作用;而中缝大核注射5-HT则为抑制作用,可能是通过5-HT2受体途径发挥作用;中缝大核微量注射5-HT的同时室旁核电刺激对胃电的抑制似具协同作用,进一步证实了中枢同时存在"下行性抑制"和"下行性兴奋"两个系统共同调控消化道功能的概念.AIM： To observe the effects of microinjection of 5-hydroxytryptamine （5-HT） and its blocking agents into the paraventricular nucleus （PVN） and nucleus raphe magnus （RM） and microelectric stimulation of the PVN on gastric electrical activity （GEA） in rabbits, and explore the central role of the PVN in controlling gastrointestinal movement. METHODS： The stereopositioning of the PVNand RM was performed using a stereo positioner （model SN-2）. Microinjection of 5-HT and its blocking agents ondansetron and cyproheptadine into the PVN and RM and electrical stimulation of the PVN were then performed. GEA was measured using four bipolar serosal electrodes （gastric body I-III and gastric antrum） in a rabbit. The parameters of GEA detected included average frequency, phase difference, the ratio of negative phase, amplitude, etc. RESULTS： Paraventricular injection of 2 μg of 5-HT accelerated the electric frequencies of gastric body I-II and gastric antrum, and the change in the electric frequency of gastric body II was statistically signifi cant （4.44 ± 0.09 vs 4.24 ± 0.09, P = 0.034）. Subsequent microinjection of 5 μg of ondansetron slowed down the frequencies of gastric body I-III and gastric antrum, and the changes in the frequencies of gastric body II-III were statistically signifi cant （P = 0.032 and 0.043, respectively）. Microinjection of 5 μg of cyproheptadine following 5-HT injection accelerated the electric frequencies of gastric body I-II and gastric antrum, and the change in the electric frequency of gastric body II was statistically signif icant （P = 0.044）. Elelctric stimulation of the PVN slowed down the frequencies of gastric body I and III and gastric antrum, and the changes in the frequencies of gastric body I and III were statistically signifi cant （P = 0.030 and 0.029, respectively）. Microinjection of 10 μg of 5-HT into the RM signifi cantly slowed down the frequency of gastric body II （4.13 ± 0.11 vs 4.33 ± 0.09, P = 0.021）, while subsequent in

关 键 词：5-羟色胺 室旁核 中缝大核 昂丹司琼 赛庚啶 

分 类 号：R573[医药卫生—消化系统]