Mayrand S, Diamant N E
Department of Medicine, University of Toronto, Ontario, Canada.
Gastroenterology. 1993 Nov;105(5):1411-20. doi: 10.1016/0016-5085(93)90146-4.
Conventional perfused manometry has led to extensive study of phasic contractile activity in the human esophagus, but little is known about esophageal tonic activity. The aims of this study were to assess esophageal smooth and striated muscle tone and the effect of a smooth muscle relaxant (amyl nitrite, 0.3 mL inhalation) on this tone.
Using a computerized isobaric recording system (barostat), esophageal tonic activity in 13 healthy subjects was recorded. Two parameters were analyzed: compliance and resistance to initial stretch (resting tone).
The smooth muscle esophagus was significantly more compliant but presented a greater resistance to initial stretch than the striated muscle section. Amyl nitrite affected only the smooth muscle section, significantly increasing compliance and decreasing the resistance to initial stretch. Significant chest pain and/or discomfort occurred only during striated muscle esophagus distension (10 of the 13 subjects at 25 mm Hg distending pressure).
Active tone is present in the smooth muscle esophagus and can be modulated by a smooth muscle relaxant. Compliance and resting tone differ between the smooth and striated muscle segments of the esophagus. Assessment of tone in patients with esophageal motor disorders and noncardiac chest pain should provide further insights into these disorders.
传统的灌注测压法已促使人们对人类食管的阶段性收缩活动进行了广泛研究，但对食管的张力活动了解甚少。本研究的目的是评估食管平滑肌和横纹肌的张力，以及平滑肌松弛剂（亚硝酸异戊酯，吸入0.3 mL）对这种张力的影响。
使用计算机化等压记录系统（恒压器）记录13名健康受试者的食管张力活动。分析了两个参数：顺应性和对初始拉伸的阻力（静息张力）。
平滑肌食管的顺应性明显更高，但与横纹肌部分相比，对初始拉伸的阻力更大。亚硝酸异戊酯仅影响平滑肌部分，显著增加顺应性并降低对初始拉伸的阻力。仅在横纹肌食管扩张期间（13名受试者中有10名在25 mmHg扩张压力下）出现明显的胸痛和/或不适。
食管平滑肌存在主动张力，可被平滑肌松弛剂调节。食管平滑肌和横纹肌段的顺应性和静息张力不同。评估食管运动障碍和非心源性胸痛患者的张力应能为这些疾病提供进一步的见解。
