【作者】 孙一耕；

【导师】 艾洪滨； 崔希云；

【作者基本信息】 山东师范大学 ， 动物学， 2007， 硕士

【摘要】 最后区(AP)作为迷走复合体(DVC)的组成部分之一,同迷走神经背核(DMV)、孤束核(NTS),共同构成了集内脏感觉信息的传入、整合、内脏运动信息的传出于一体的内脏副交感神经中枢。这个中枢调控着胃的运动机能和分泌机能。有关大鼠DMV和NTS对胃运动机能的影响,其他实验室及本实验室已有研究报道。但大鼠的AP对胃的运动机能有何影响,至今未见文献报道。本研究利用化学刺激和电刺激两种方法探讨了AP对胃运动的影响。本文化学刺激的方法,向AP内微量注射不同浓度的神经元胞体兴奋剂L-Glu,对照组注射生理盐水。L-Glu的浓度分别为:0.1mol/L,0.2mol/L和0.5mol/L。用胃腔内放置水囊法和二道生理记录仪全程记录AP内微量注射药物前、后的胃运动曲线。分别统计大鼠在注药前、后各5min内胃收缩波的幅度、时程、频率以及胃运动指数。结果:三种不同浓度的L-Glu被注射到最后区后对胃运动均具有抑制作用,而且这种抑制具有剂量依赖性:三种浓度的L-Glu对胃运动指数的抑制率分别为36.03%,72.09%,96.91%。注射生理盐水组胃运动指数的抑制率为-7.25%在记录胃运动的同时记录呼吸和心率。经统计学处理结果,化学刺激最后区对呼吸基本没有影响,对心率有显著的抑制作用。本文电刺激的方法,采用BL-420生物机能系统的刺激输出,电刺激参数为:连续单刺激,频率30Hz,强度0.15mA,波宽0.30ms。连续刺激5min,间隔10min后再进行第二次刺激,以保证第一次刺激对胃运动的作用不会影响到下一次刺激的效果。结果:电刺激大鼠最后区同样对胃运动具有抑制作用。第一次刺激的抑制率为52.44%;第二次刺激的抑制率为57.50%。与化学刺激相同,电刺激AP对呼吸无影响,对心率有显著的抑制作用。这些结果充分表明,最后区兴奋能抑制胃的运动。为了探讨最后区兴奋对胃运动起抑制作用的传出神经通路,做了膈肌下迷走神经切断实验。结果,切断膈肌下双侧迷走神经后,再以同样的电刺激参数刺激最后区,消除了抑制胃运动的效应。表明最后区对胃运动抑制的传出神经通路是迷走神经。更多还原

【Abstract】 The dorsal vagal complex (DVC) is composed of the dorsal motor nucleus of vagus (DMV), the nucleus of solitary tract (NTS) and the area postrema (AP). It is a parasympathetic preganglionic centre of gastric function, especially gastric motility. Other laboratories and our laboratory have reported the effects of electrical and chemical stimulation of DMV and NTS on the gastric motility in rats. All correlative papers published up to now indicated that the excitation of NTS inhibited the gastric motility, but some researches showed that the excitation of DMV enhanced the gastric motility while others, reduced the gastric motility. But, the effects of excitation of AP on gastric motility have not been reported so far. In this study, we observed the effects of chemical stimulation and electrical stimulation of AP on gastric motility and the efferent nervous pathway was probed.In the chemical stimulation experiment, 0.2μl of 0.1mol/L, 0.2mol/L, 0.5mol/L L-Glutamine solution were respectively microinjected into AP. Physiological saline was microinjected into AP in the control group. Gastric motility curves were recorded with water-filled balloons placed into stomach and two-lead physiological recorder. The frequency, duration, amplitude and motility index of gastric contractive waves within 5 min before and after microinjection were analyzed. The results showed that all the three kinds of concentration of L-Glu led to significant inhibitory effects on gastric motility. Moreover, the inhibitory extent was enhanced with the increase of L-Glu concentration. The inhibitory rates of gastric motility index were: 36.03%, 72.09%, 96.91%, respectively. Meanwhile, no obvious influence was observed after physiological saline was microinjected into AP. Respiration and heart rate were recorded at the same time. It showed that chemical stimulations inhibited heart rate while respiration did not show obvious change.In the electrical stimulation experiment, BL-420 was used to give electrical stimulus. The simulation parameters were: 30Hz, 0.15mA, 0.3ms.The stimulation lasted for 5 min. The second stimulation was performed after an interval of 15mins in order to relieve the effect of the first stimulation. Results: the inhibitory rates of gastric motility index by two stimulations were 52.44%, 57.50% respectively. It showed that electrical stimulation of AP led to significant inhibition on gastric motility. Similar to the effects of chemical stimulation, electrical stimulation had no effects on respiration but did inhibit heart rate.The results mentioned above suggested that the excitation of AP inhibited gastric motility.The gastric motility was not significant changed during stimulating AP after the vagus nerves beneath diaphragma were cut. The results showed that the inhibitory effects of AP on gastric motility were withdrawn by the vagus nerves vagotomy beneath diaphragma. The results indicate that the efferent nerve pathway of AP inhibiting gastric motility is vagus in rats.更多还原