Thompson D G, Andreollo N A, McIntyre A S, Earlam R J
Department of Gastroenterology, London Hospital, Whitechapel.
Gut. 1988 Jul;29(7):881-5. doi: 10.1136/gut.29.7.881.
Contraction of the upper oesophageal sphincter combined with secondary peristalsis clears the oesophagus of refluxed gastric contents and protects the trachea, but the nature of these reflex stimuli remains controversial. Secondary peristaltic and sphincteric responses were measured during intraluminal infusion of 0.1 N hydrochloric acid and equiosmolar saline solutions in seven normal volunteers. Responses to a single volume infused at varying sites in the oesophagus and to progressively increasing volumes of test solution were measured. In addition oesophageal responses to similar degrees of distension induced by inflation of an intraluminal balloon were also recorded. The sphincteric responses to both stimuli were similar, decreasing in value with distance from the sphincter from values of 70 (68-85) mmHg (median (range] for HCl; and 70 (55-85) mmHg for NaCl at 5 cm below the sphincter to 40 (30-60) mmHg for both HCl and NaCl at 20 cm. As the volume of the solution infused into the proximal oesophagus was increased, the sphincter pressure also rose from a median basal value of 30 (25-50) mmHg to 40 (30-50) mmHg for HCl and NaCl after 1 ml, while after 7 ml infusion, the responses were greater, 65 (45-85) mmHg for HCl, and 60 (45-80) mmHg for NaCl. In the more distal oesophagus, responses were qualitatively similar but quantitatively smaller than proximally, being 30 (25-40) mmHg for HCl and 30 (25-50) mmHg for NaCl following 1 ml and 45 (40-55) mmHg for HCl and NaCl after 7 ml. Secondary peristalsis was also induced equally by both solutions and varied with volumes infused and site of infusion in a manner similar to the sphincter responses. After a 7 ml/min acid infusion 14 (1- 40) secondary contractions/three min were recorded at 5 cm and eight (2 - 18)/three min were recorded at 20 cm. Values for saline were similar, 13 (1- 38)/three min at 5 cm and eight (4 - 25)/three min at 20 cm. Oesophageal distension by a balloon positioned 10 cm below the sphincter induced identical clearance responses to those seen after similar volumes of either acid or saline infused at the same site. These results suggest that the principal stimulus for upper oesophageal clearance is intraluminal distension and do not support the idea that the oesophagus is pH sensitive.
食管上括约肌收缩与继发性蠕动相结合，可清除食管内反流的胃内容物并保护气管，但这些反射刺激的性质仍存在争议。在7名正常志愿者腔内注入0.1N盐酸和等渗盐溶液期间，测量了继发性蠕动和括约肌反应。测量了在食管不同部位注入单一容量溶液以及逐渐增加测试溶液容量时的反应。此外，还记录了食管对腔内球囊充气引起的类似程度扩张的反应。两种刺激引起的括约肌反应相似，随着与括约肌距离的增加而降低，在括约肌下方5cm处，盐酸刺激时的值为70（68 - 85）mmHg（中位数[范围]），氯化钠刺激时为70（55 - 85）mmHg；在20cm处，盐酸和氯化钠刺激时均为40（30 - 60）mmHg。随着注入食管近端溶液体积的增加，括约肌压力也从30（25 - 50）mmHg的中位数基础值上升，注入1ml盐酸和氯化钠后分别升至40（30 - 50）mmHg，注入7ml后反应更大，盐酸刺激时为65（45 - 85）mmHg，氯化钠刺激时为60（45 - 80）mmHg。在食管更远端，反应在性质上相似，但在数量上比近端小，注入1ml后，盐酸刺激时为30（25 - 40）mmHg，氯化钠刺激时为30（25 - 50）mmHg；注入7ml后，盐酸和氯化钠刺激时均为45（40 - 55）mmHg。两种溶液引起的继发性蠕动也相同，并且与注入体积和注入部位有关，方式与括约肌反应相似。以7ml/min注入酸溶液后，在5cm处记录到每分钟14（1 - 40）次继发性收缩，在20cm处记录到每分钟8（2 - 18）次。盐水的值相似，在5cm处为每分钟13（1 - 38）次，在20cm处为每分钟8（4 - 25）次。位于括约肌下方10cm处的球囊引起的食管扩张，产生的清除反应与在同一部位注入相同体积的酸或盐水后观察到的反应相同。这些结果表明，食管上清除的主要刺激是腔内扩张，不支持食管对pH敏感的观点。
