Excitatory and inhibitory neural regulation of canine pyloric smooth muscle.
Excitatory and inhibitory neural regulation of canine pyloric smooth muscle.
复制标题
犬幽门平滑肌的兴奋性和抑制性神经调节。
DOI：
10.1152/ajpgi.1990.259.1.g125
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Sanders,KM
中科院分区：
文献类型：
--
作者：
Vogalis,F;Sanders,KM
本研究旨在探讨犬幽门环肌层的内在神经支配。用细胞内记录技术研究肌横截面，并用跨壁神经刺激引起连接电位。通过圆形层的厚度在几个点处记录来自细胞的神经介导的反应。兴奋性连接电位（EJPs）的幅度增加，抑制性连接电位（IJPs）的幅度降低，从肌间边缘的环形肌。阿托品阻断EJPs在整个循环层，表明兴奋性输入主要是胆碱能。阻断EJPs后，IJP振幅的梯度持续存在。鉴定了IJPs的三种组分：1）快速、apamin敏感组分，其在约1 s内达到峰值并衰减; 2）较慢、apamin不敏感组分，其在800 ms内达到峰值，但在5 s内缓慢衰减; 3）非常缓慢的组分，其在7-10 s内达到最大值。连接电位影响肌源性电活动的模式。电刺激可引起环层肌间部分的过早慢波，但当兴奋性输入被阻断时，IJPs大大降低了慢波的振幅。EJPs在环形肌的粘膜下部分引起动作电位，IJPs使这些细胞超极化。还描述了内源性神经对幽门肌收缩模式的影响。这些数据表明，在胃十二指肠交界处存在一个神经肌肉装置，用于1）慢波的局部调节和2）环形层的肌间和粘膜下区域的独立控制。
Studies were performed to characterize the intrinsic innervation of the circular muscle layer of the canine pylorus. Cross-sectional strips of muscle were studied with intracellular recording techniques, and junction potentials were elicited with transmural nerve stimulation. Neurally mediated responses were recorded from cells at several points through the thickness of the circular layer. Excitatory junction potentials (EJPs) increased and inhibitory junction potentials (IJPs) decreased in amplitude with distance from the myenteric border of the circular muscle. Atropine blocked EJPs throughout the circular layer, demonstrating that excitatory inputs are primarily cholinergic. The gradient in IJP amplitude persisted after blockade of EJPs. Three components of IJPs were identified: 1) a fast, apamin-sensitive component that reached a peak and decayed within approximately 1 s; 2) a slower, apamin-insensitive component that reached a peak within 800 ms but decayed slowly over 5 s; and 3) a very slow component that reached a maximum in 7-10 s. Junctional potentials affected the pattern of myogenic electrical activity. Transmural stimulation could evoke premature slow waves in the myenteric portion of the circular layer but when excitatory inputs were blocked, IJPs greatly reduced the amplitude of slow waves. EJPs elicited action potentials in submucosal portion of circular muscles, and IJPs hyperpolarized these cells. The influence of intrinsic nerves on contractile patterns of pyloric muscles was also characterized. These data demonstrate that a neuromuscular apparatus exists within the gastroduodenal junction for 1) local regulation of slow waves and 2) independent control of the myenteric and submucosal regions of the circular layer.