Propagation of slow waves in the guinea-pig gastric antrum
Propagation of slow waves in the guinea-pig gastric antrum
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DOI：
10.1113/jphysiol.2005.100735
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发表时间：
2006-02-15
影响因子：
5.5
通讯作者：
Edwards, FR
中科院分区：
文献类型：
--
作者：
Hirst, GDS;Garcia-Londoño, AP;Edwards, FR
细胞内记录是从豚鼠胃窦完整肌肉壁的圆形层进行的，其中大部分胃体仍然附着。当两个电极平行并靠近大弯时，首先在口腔部位检测到慢波，随后在肛门部位检测到：口腔-肛门传导速度为2.5 mm s(-1)。当一个电极位于大曲率附近而另一个电极位于圆周位置时，首先在大曲率附近检测到慢波，随后在圆周位置检测到：圆周传导速度为13.9 mm s(-1)。当用已去除环形肌层的制剂进行记录时，口腔肛门和圆周传导速度均为约3.5mm s(-1)。当从大部分窦间质细胞肌间网络（ICCMY）被解剖掉的制剂中记录慢波时，首先在完整的ICCMY区域附近检测到慢波，然后在圆周位置检测到：在没有ICCMY的区域中慢波的圆周传导速度为14.7 mm s（-1）。当确定孤立的单束圆形肌肉的电特性时，它们的长度常数约为3毫米，时间常数约为230毫秒，渐近电紧张传播速度为25毫米秒（-1）。研究发现，相邻环状肌束之间的口腔肛门电耦合差异很大：一些肌束与相邻肌束连接良好，而另一些则不然。总之，观察结果表明，慢波的缓慢口腔肛门进展是由于间质细胞肌间网络中起搏器电位的缓慢传导速度造成的。 The rapid circumferential conduction of slow waves results from the electrical properties of the circular muscle layer which allow intramuscular ICC (ICCIM) to support the radial spread of slow waves: regions of high resistance between bundles prevent the anally directed spread of slow waves within the circular layer.
Intracellular recordings were made from the circular layer of the intact muscular wall of the guinea-pig gastric antrum in preparations where much of the corpus remained attached. When two electrodes were positioned parallel to and near to the greater curvature, slow waves were first detected at the oral site and subsequently at the anal site: the oro-anal conduction velocity was found to be 2.5 mm s(-1). When one electrode was positioned near the greater curvature and the other at a circumferential location, slow waves were first detected near the greater curvature and subsequently at the circumferential site: the circumferential conduction velocity was 13.9 mm s(-1). When recordings were made from preparations in which the circular muscle layer had been removed, the oro-anal and the circumferential conduction velocities were both about 3.5 mm s(-1). When slow waves were recorded from preparations in which much of the myenteric network of antral interstitial cells (ICCMY) had been dissected away, slow waves were first detected near the region of intact ICCMY and subsequently at a circumferential location: the circumferential conduction velocity of slow waves in regions devoid of ICCMY was 14.7 mm s(-1). When the electrical properties of isolated single bundles of circular muscle were determined, their length constants were about 3 mm and their time constant about 230 ms, giving an asymptotic electrotonic propagation velocity of 25 mm s(-1). Oro-anal electrical coupling between adjacent bundles of circular muscle was found to vary widely: some bundles were well connected to neighbouring bundles whereas others were not. Together the observations suggest that the slow oro-anal progression of slow waves results from a slow conduction velocity of pacemaker potentials in the myenteric network of interstitial cells. The rapid circumferential conduction of slow waves results from the electrical properties of the circular muscle layer which allow intramuscular ICC (ICCIM) to support the radial spread of slow waves: regions of high resistance between bundles prevent the anally directed spread of slow waves within the circular layer.