【作者】 孟立；

【导师】 陆杰；

【作者基本信息】 重庆医科大学 ， 生理学， 2004， 硕士

【摘要】 目的：研究CCK对胃肠感觉传入冲动的影响方法：实验在86只Wistar大鼠上进行，记录扩张胃引起的膈下迷走传入放电的变化,观察外周静脉注射不同剂量的CCK（0.03、0.06、0.12μg/kg）或十二指肠灌注酪蛋白（Casein）诱发内源性CCK的分泌，了解外源性及内源性CCK对迷走神经自发放电及扩胃-诱发迷走传入放电的影响以及不同的扩胃容量对其产生的量效反应。同时记录了胃肠感觉传入冲动在孤束核区域内的投射情况。并以HRV为指标观察了迷走神经传入冲动变化对植物神经中枢的影响。结果：1.扩张胃对迷走神经传入冲动的影响效果明显，从0.5~5ml，随扩张容量的增加，迷走自发传入放电逐步增多，到扩张容量为3ml时自发传入冲动达最大值（p＜0.05)。2.静脉注射不同剂量的CCK对迷走传入放电反应的影响不同。小剂量对自发放电没有明显作用（p＞0.05），中剂量对自发放电有明显兴奋作用，注后即刻放电增加，大剂量出现作用迅速而持久（p＜0.05)。3. 十二指肠灌注酪蛋白对迷走神经自发放电作用非常明显，注后5min即引起迷走神经传入冲动明显增加，在观察的 1h内一直保持兴奋效应（p＜0.05)；对于扩胃-迷走传入诱发放电反应没有明显刺激作用（p＞0.05）。4.CCK+Sec对迷走传入的影响：静脉注射大剂量CCK后即刻使迷走神经自发放电增多，而大剂量CCK+SEC可翻转由CCK所致的迷走神经传入放电增多（p＜0.05）。5. 胃肠感觉传入在孤束核区域内的投射情况: 观察了21只大鼠，共记录了125个神经元。其中与胃扩张刺<WP=7>激相关的有13个，其中兴奋神经元有10个，占76.9%。与刺激膈下迷走神经相关的有15个，12个呈抑制效应，占80%。与刺激颈部迷走神经相关的有33个。其中兴奋神经元有22个，占67%。在刺激迷走神经（膈下和颈部迷走神经）相关的神经元中，与两者都相关的神经元有12个。6.CCK对HRV谱参数的影响:小剂量CCK使心率加快,迷走神经张力减低.中大剂量对心率没有明显的刺激作用。实验结果均以X±SD来表示,用SPSS统计软件作单因素方差分析，以P<0.05为有显著性差异。结论：CCK对迷走神经传入自发放电有刺激作用CCK对胃壁的机械感受器有抑制作用促胰液素可抑制由CCK引起的迷走传入自发放电增多的现象CCK可以通过降低迷走中枢紧张性使心率加快CCK对胃肠的感觉传入有重要的调节作用.更多还原

【Abstract】 AIM：To study the effect of cholecystokinin on gastrointestinal tract sensation afferent impulse.Method：Gastric distention - induced changes of afferent discharge of subdiaphragmatic vagus nerve was recorded in 86 Wistar rats. We investigated the effect of ectogenous and endogenous CCK on auto-discharges of vagus nerve and gastric distention induced-discharges as well as the effect of different volume of distention to vagal discharge by intravenous injection of different dosage of CCK (0.03、0.06、0.12μg/kg), duodenal infusion of Casein to evoke the excretion of CCK. The projection of the gastrointestinal tract sensation afferent impulses in the nucleus of solitary tract was also observed and the effect of changes in vagal afferent impulse to vegetative nervous system was investigated by HRV.Result：1. Gastric distention had obvious effect on the afferent impulse of vagus nerve. In the range of 0.5 ~ 5 ml, the auto-discharges of vagus afferent nerve were increased gradually with increasing distention volume step by step. When the distention volume was 3ml or more, the <WP=9>auto-discharges were achieved the maximum (p < 0.05). 2. Different dosage of CCK had different effect on vagus afferent discharges: CCK of low dose had no significant effect (p < 0.05); middle dose significantly enhanced vagal discharge immediately after injection; high dose showed a quick effect which lasted for a long time (p < 0.05). 3. Duodenal infusion of Casein had obvious effect on auto-discharge of vagus nerve. Afferent discharge increased markedly 5 minute after infusion and the effect lasted in the observed 1 hour (p < 0.05). Duodenal infusion of Casein had no significant effect on gastric distention-induced vagal discharge (p > 0.05). 4.The effect of CCK + SEC on vagal afferent impulse: the auto-discharge of vagus nerve was increased immediately after intravenous injection of high dose CCK while high dose CCK plus secretin could reverse the effect (p < 0.05). 5. The projection of gastrointestinal tract sensation afferent impulses in the nucleus of solitary tract: in the 21 rats, 125 neurons were recorded. 13 of the total neurons were gastric distention related, among which 10 were excitatory ones (the proportion is 76.9%). 15 of the total were subdiaphragmatic vagus nerve stimulation related, among which 12 were inhibitory ones (the proportion is 80%). 33 of the total were cervical vagus nerve stimulation related, among which 22 were excitatory ones (the proportion is 67%). In the vagus nerve (subdiaphragmatic and cervical vagus nerve) stimulation related neurons, 12 were related to both. 6. The effect of CCK on HRV <WP=10>spectrum parameters: CCK of low dose caused tachycardia and decreased vagal tension, while CCK of middle and high dose had no significant effect on heart rate.Results were expressed as mean ± SE. Statistical significance was assessed by using the one-way ANOVA with SPSS software, and data were regarded as significant at a p value of < 0.05.Conclusion: CCK has excitatory effect on auto-discharge of vagus afferent nerve.CCK has inhibitory effect on gastric mechanism receptors, which were fast (rapid) adaptation receptors. Secretin can inhibit CCK induced auto-discharge increase of vagus afferent nerve.CCK can affect heart rate by vagus nerve.CCK is important in modulation sensation afferent impulse of gastrointestinal tract.更多还原