设为首页
加入收藏
求医中医药网
www.qe.cn
站内搜索
锋电位无变化。结论：迷走中枢经外周迷走神经和M受体控制着兔消化间期GB及SO间协调运动。
中图分类号：R541.7文献标识码：A
文章编号：1000 -6834(2000)04-0347-03
THE VAGUS NERVE COORDINATES THE MOTION OF
GALLBLADDER AND SPHINCTER OF ODDI IN THE
INTERDIGESTIVE PERIOD IN RABBITS
LIU Chuan-yong LIU Jing-zhangLI Zi-yingLIU KE-jing
（Department of Physiology,Shandong Medical University,Jinan, 2500 12）
ABSTRACTAim: To investigate the effect of vagus nerve on coordinating the motion of gallbladder (GB) and sphincter of Oddi (SO) in the interdigestive period in rabbits. Methods: Fasted for 15 h～18 h, but allowed to drink wa ter, the rabbib were anesthetized with urethane (1.0 mg/kg, iv). In order to mea sure GB pressure, a frog bladder filled with normal saline was put into GB and c onnected to a transducer (TP-200T). Myoelectric signals of SO was recorded by a pair of copper electrodes. Results: In the interdigestive peri od, phasic contractions of GB (PCGB) and clusters of spike potentials of SO (CS PSO) was 1∶1 correlated (Y=0.962X+0.587,r=0.982,P＜0.01). That is, every PCGB was accompanied by one CSPSO. Microinjection of thyrotropin-rele asing hormone (TRH, 0.8 nmol, 1 μl) or monosodium glutamate (MSG, 2 μmol, 1 μl) into dorsal vagal complex (DVC) enhanced the motility of GB and SO, and t he 1∶1 temporal relation between PCGB and CSPSO still existed. Vagotomy or intr avenous injection of atropine inhibited the PCGB and the spike potentials of SO, and the 1∶1 correlation between PCGB and CSPSO disappeared. The spike bursts o f SO did not respond to the artificial rise of gallbladder pressure. con clusion: In the interdigestive period in rabbits, gallbladder and SO con tra ct and relax rhythmically and simultaneously. This eoordinated motion between G B and SO is controlled by DVC via vagus nerve and peripheral M receptors.
KEY WORDS:
我们前一阶段的研究表明，迷走神经在调节兔消化间期胆囊位相性收缩(phasic contractio n of gallbadder,PCGB)方面起重要作用［1～3］。最近我们发现，在消化间期，兔P CGB与奥迪氏括约肌锋电位簇(clusters of spike potentials of sphincter of oddi,CSPS O)之间呈明显1∶1对应关系［4］。本实验通过迷走神经复合区(dorsal vagal compl ex,DVC)内微量注射兴奋性递质、迷走神经切断及外周受体阻断等方法，旨在探讨迷走神经 在协调消化间期胆囊(gallbladder,GB)与奥迪氏括约肌(sphincter of Oddi,SO)间协调运 动方面的作用。
1材料与方法
1.1动物分组
实验采用健康成年家兔25只，分成5组(n=5)；第一组，DVC内微量注射促甲状腺激素释 放激素(thyrotropine-releasing hormone,TRH);第二组，DVC内微量注射谷氨酸钠(monoso dium glutamate,MSG);第三组，颈部迷走神经切断；第四组，静脉注射阿托品；第五组，人 为升高胆囊内压(gallbladder pressure,GP)。
1.2动物模型制备
动物禁食但自由饮水15～ 18 h后，乌拉坦(1.0 mg/kg)静脉麻醉。常规气管插管。三碘季 胺酚(0.3 mg/kg,iv)肌松，人工呼吸(通气量30 ml×20次/min)。单侧股动脉插管监测血压 ，动物肛温维持于37.0～38.5℃。
1.3GP及SO电活动记录
动物仰卧，腹部正中切口暴露GB，在GB底部剪一3 mm的小口，将装有生理盐水的蛙膀胱置入 GB内并结扎切口，由一软橡胶管将蛙膀胱与压力换能器(TP-200T)相连；将双极康铜丝电极 固定于SO浆膜下；GB与SO的压力及电信号分别经载波放大器(AB-621G)及生物电放大器(BI -601G)放大后，在生理记录仪(RM-6000，NIHON KOHDEN)上同步记录。
1.4DVC内微量注射
将动物头固定在江湾Ⅰ型颅脑定位仪上。根据Messen图谱，将一外径为0.5 mm的定向钢管 插入DVC内(闩前0.5～1.0 mm,旁开0.7～1.2 mm，深0.5～1.2 mm)。将所要注射药物 按所需剂量配制成1 μl,用容量为5 μl的微量注射器沿定向导管缓缓注入DVC内，注射时间 1 min。实验结束后用直流电烧灼注药位点，福尔马林固定后冰冻切片，光镜下观察注药位 点。
1.5统计学分析
将3 min内PCGB与CSPSO数量间相关关系进行分析，将r值进行t检验，在有直线相关 的两变量间作回归方程。在第五组，将人为升高GP前后SO电活动的积分值进行配对t检验。
2结果
2.1DVC内微量注射TRH
消化间期胆囊呈现周期性、位相性收缩，每一次PCGB能将GP升高0.010～0.060 kPa。SO锋 电位也呈簇集发放，每一次PCGB往往同时伴随一次CSPSO 。3 min内PCGB的平均数量()与同一段时间内CSPSO数()几乎相等(r=0.982,P＜0.01,= 0.962+0.587,n=5)，且呈现明显的1∶1对应关系(图1，control)。
Fig.1 The 1∶1 temporal relatio n between the phasic contraction
of gallbladder (PCGB) and the cluster of the s pike potentials
of sphincter of Oddi (CSPSO) before and after injection of thyro
tropin-releasing hormone(TRH) (0.8 nml, 1 μl) into dorsal vagal
complex (DVC) . A, gallbladder pressure, B, spike potentials of sphincter
of Oddi. ↓inject TRH into DVC
TRH(0.8 nmol,1 μl)注入DVC内后，PCGB与SO锋电位明显增强，PCGB与CSPSO间1∶1对应关 系依然存在(r=0.976,P＜0.01,=0.963+0.085,n=5 )(图1)。
2.2DVC内微量注射MSG
将MSG(0.2 μmol,1 μl)注射到DVC后，PCGB与SO锋电位明显增强，注药后5～20 min内，P CGB与CSPSO间1∶1对应关系依然存在(r=0.981,P＜0.01,=1.035x-0.415, n=5)(图2)。
Fig.2 The 1∶1 temporal relatio n between the phasic
contraction of gallbladder (PCGB) and the cluster of
the sp ik potentials of sphincter of Oddi (CSPSO) before and
after injection of monoso dium glutamate (MSG) (0.2 μ mol, 1 μl)
into dorsal vagal complex (DVC).A, gall bladder pressure.
B, spike potentials of sphincter of Oddi.
2.3双侧颈部迷走神经切断
在第三组，双侧颈部迷走神经分离并切断，在神经切断后30 min内，PCGB与SO锋电位明显抑 制，PCGB与CSPSO间1∶1对应关系消失(r=-0.213,P＜0.05,n=5)(图3)。
