Motoneurones of the submucous plexus regulate electrical activity of the circular muscle of canine proximal colon.
Motoneurones of the submucous plexus regulate electrical activity of the circular muscle of canine proximal colon.
复制标题
粘膜下神经丛的运动神经元调节犬近端结肠环形肌的电活动。
DOI：
10.1113/jphysiol.1986.sp016286
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Smith,TK
中科院分区：
文献类型：
--
作者：
Sanders,KM;Smith,TK
对犬近端结肠的环形肌从粘膜下神经丛的神经元接受运动输入的假设进行了检验。用微电极刺穿环形肌细胞，并通过电场刺激和乙酰胆碱（ACh）微喷射刺激粘膜下神经丛神经元。在阿托品阻断直接毒蕈碱效应的情况下，将ACh微喷射到粘膜下神经节的粘膜下诱发：（i）抑制性连接电位（i. j. p.）这降低了随后的慢波的幅度、持续时间和上升速率;（ii）在初始抑制反应之后持续时间增加的慢波。这些反应增强了乙酰胆碱的体积管理。对ACh的反应被10（-4）M的六甲铵、10（-4）M的d-筒箭毒碱或10（-6）M的河豚毒素（TTX）阻断，表明它们是神经源性的。抑制性和兴奋性反应都是非胆碱能和非肾上腺素能神经的结果。介导这些效应的递质尚不清楚。去除纵肌、肌间神经丛和环形肌的浆膜部分对将ACh应用于粘膜下神经节的反应没有明显影响。在这些制剂中，对场刺激的反应与ACh产生的反应相同。粘膜下神经丛也为环行肌提供胆碱能输入。当ACh作用于粘膜下层时，可引起肌细胞的胆碱能反应，而六烃季铵或TTX可显著减弱这种反应。这些结果表明，胆碱能反应的结果ACh释放的神经元在效应，而不是溢出的外源性ACh。在去除肌间神经丛的制剂中也引起了胆碱能反应。近端结肠环行肌中的慢波在没有Ca 2+动作电位的情况下产生兴奋-收缩耦合。因此，粘膜下神经元对电慢波的影响对运动活动有直接影响。通过i.j.p.s.降低慢波的振幅和持续时间。导致阶段性收缩的幅度和持续时间减少。兴奋性输入增强收缩。这些数据支持了一个新的概念：从粘膜下神经节发出的运动神经元支配环形肌肉，并提供抑制和兴奋性输入来调节慢波活动。（400字处截断摘要）
The hypothesis that the circular muscle of the canine proximal colon receives motor input from neurones in the submucous plexus was tested. Circular muscle cells were impaled with micro‐electrodes and submucous plexus neurones were stimulated by electrical field stimulation and microejection of acetylcholine (ACh). In the presence of atropine to block the direct muscarinic effects, microejection of ACh onto the submucosa where intact submucous ganglia were suspended evoked: (i) an inhibitory junction potential (i.j.p.) that reduced the amplitude, duration and rate of rise of the subsequent slow wave; (ii) a slow wave of increased duration following the initial inhibitory response. These responses were enhanced by increasing the volume of ACh administered. Responses to ACh were blocked by hexamethonium, 10(‐4) M; d‐tubocurarine, 10(‐4) M; or tetrodotoxin (TTX), 10(‐6) M, suggesting they were neural in origin. Both inhibitory and excitatory responses were the result of non‐cholinergic and non‐adrenergic nerves. The transmitters mediating these effects are unknown. Removal of the longitudinal muscle, myenteric plexus, and the serosal portion of the circular muscle had no apparent effect on the responses to application of ACh to submucosal ganglia. In these preparations the responses to field stimulation were identical to those produced by ACh. The submucous plexus also provides cholinergic input to the circular muscle. When ACh was discretely applied to the submucosa cholinergic responses were elicited at the muscle cell which were significantly reduced by hexamethonium or TTX. These findings suggest that the cholinergic responses were the result of ACh release by neurones at the effector and not by overflow of the exogenous ACh. Cholinergic responses were also elicited in preparations in which the myenteric plexus had been removed. Slow waves in circular muscle of the proximal colon yield excitation‐contraction coupling in the absence of Ca2+ action potentials. Therefore the influence of submucous neurones on electrical slow waves has direct consequences on motor activity. Reduction in the amplitude and duration of slow wave by i.j.p.s. results in reduction in the amplitude and duration of phasic contractions. Excitatory inputs enhance contractions. The data support a new concept: motoneurones emanating from submucous ganglia innervate the circular muscle and provide inhibitory and excitatory inputs to regulate slow wave activity.(ABSTRACT TRUNCATED AT 400 WORDS)