Altschuler S M, Boyle J T, Nixon T E, Pack A I, Cohen S
Am J Physiol. 1985 Nov;249(5 Pt 1):G586-91. doi: 10.1152/ajpgi.1985.249.5.G586.
We have previously suggested that both the lower esophageal sphincter and diaphragm contribute to the high-pressure zone (HPZ) at the gastroesophageal junction. The purpose of this study in anesthetized cats was to compare changes in diaphragmatic electrical activity with changes in the intraluminal pressure profile in the HPZ following either balloon distension of the esophagus or swallowing evoked by pharyngeal stimulation. Intraluminal pressure was continuously recorded by a perfused manometric assembly anchored to the gastric fundus through an abdominal surgical approach. Integrated EMG was simultaneously measured in the costal and crural parts of the diaphragm. Our results indicate that simultaneous relaxation of the lower esophageal sphincter (LES) and crural diaphragm follows both swallowing and balloon distension of the esophagus; during swallowing both inhibitory reflexes depend on the initiation of esophageal peristalsis; crural relaxation abolishes respiratory-induced pressure oscillations in the HPZ during LES relaxation; ventilation is maintained during relaxation of the HPZ in part by continued contraction of the costal diaphragm; and different neural pathways control LES relaxation and crural relaxation. The data support the view that the crural diaphragm augments the intrinsic smooth muscle sphincter mechanism at the gastroesophageal junction and that crural relaxation may be an important factor in mouth-to-gastric transit.
我们之前曾提出，食管下括约肌和膈肌均对胃食管交界处的高压区（HPZ）有贡献。本研究在麻醉猫身上进行，目的是比较食管球囊扩张或咽部刺激诱发吞咽后，膈肌电活动变化与HPZ腔内压力曲线变化。腔内压力通过经腹部手术途径固定于胃底的灌注测压装置连续记录。同时在膈肌的肋部和脚部测量肌电图积分。我们的结果表明，食管下括约肌（LES）和膈肌脚部会在吞咽及食管球囊扩张后同时松弛；吞咽过程中，两种抑制性反射均依赖于食管蠕动的启动；在LES松弛期间，膈肌脚部松弛可消除HPZ中呼吸诱导的压力振荡；在HPZ松弛期间，部分通过肋部膈肌的持续收缩维持通气；并且不同的神经通路控制LES松弛和膈肌脚部松弛。这些数据支持以下观点，即膈肌脚部增强了胃食管交界处的内在平滑肌括约肌机制，且膈肌脚部松弛可能是口到胃转运的一个重要因素。
