ROLE OF THE DIAPHRAGM IN THE GENESIS OF LOWER ESOPHAGEAL SPHINCTER PRESSURE IN THE CAT
ROLE OF THE DIAPHRAGM IN THE GENESIS OF LOWER ESOPHAGEAL SPHINCTER PRESSURE IN THE CAT
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DOI：
10.1016/0016-5085(85)90143-x
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发表时间：
1985-01-01
期刊：
影响因子：
29.4
通讯作者：
COHEN, S
中科院分区：
文献类型：
--
作者：
BOYLE, JT;ALTSCHULER, SM;COHEN, S
为了确定横膈膜在食管下括约肌（LES）高压区形成中的作用，研究了10只麻醉的成年猫横膈膜收缩对食管下括约肌压力的影响。尽管将压力记录组件锚定在LES内以防止呼吸时括约肌相对于压力记录端口的轴向运动，但LES压力的平均振荡为17.4 +-。5.5 mm Hg，频率与呼吸频率相同。末梢吸气时LES压力出现峰值，与膈肌电图峰值相对应。在手动过度通气引起的中枢性呼吸暂停期间，膈肌电图和LES压振荡均无。呼吸暂停时的LES压等于自主呼吸时的呼气末压。在泮库溴铵完全阻断神经肌肉后，潮汐量增加的人工呼吸导致压力振荡增加。然而，即使在潮汐量为正常的4倍时，压力振荡的幅度也总是显著低于自发呼吸时所观察到的。此外，通过呼吸5%的二氧化碳逐步增强膈肌电活动，揭示了个体动物呼吸诱导的LES压力振荡幅度与膈肌电峰值积分之间的线性相关。自发性呼吸时的呼气末压力最能近似反映内在LES张力。呼吸引起的LES压力波动主要是主动膈肌收缩的结果。横膈膜电活动的水平直接影响压力振荡的幅度。
To determine the role of the diaphragm in the genesis of the high-pressure zone at the lower esophageal sphincter (LES), the effect of diaphragmatic contraction on lower esophageal sphincter pressure was studied in 10 anesthetized adult cats. Despite anchoring the pressure recording assembly within the LES to prevent axial movement of the sphincter during respiration relative to the pressure recording ports, there was an average oscillation in LES pressure of 17.4 .+-. 5.5 mm Hg, the frequency of which was the same as the respiratory rate. Peak LES pressure occurred at end-inspiration corresponding with peak diaphragmatic electromyogram. During periods of central apnea induced by manual hyperventilation there was absence of both diaphragmatic electromyogram and the oscillations in LES pressure. LES pressure during apnea was equal to end-expiratory pressure during spontaneous respiration. Following complete neuromuscular blockade with pancuronium, artificial respiration with increasing tidal volumes resulted in increasing oscillations in pressure. However, the magnitude of the pressure oscillation even at tidal volumes 4 times normal was always significantly below that observed during spontaneous eupnic respiration. Furthermore, progressive augmentation of diaphragmatic electromyogram activity by breathing 5% CO2 in air revealed a linear correlation between the magnitude of the respiratory-induced pressure oscillations of the LES and peak integrated diaphragmatic electromyogram in individual animals. Intrinsic LES tone is best approximated by end-expiratory pressure during spontaneous respiration. The respiratory-induced oscillations in LES pressure are primarly the result of active diaphragmatic contraction. The level of diaphragmatic electrical activity directly influences the magnitude of the pressure oscillation.