HYPERVENTILATION, CENTRAL AUTONOMIC CONTROL, AND COLONIC TONE IN HUMANS
HYPERVENTILATION, CENTRAL AUTONOMIC CONTROL, AND COLONIC TONE IN HUMANS
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DOI：
10.1136/gut.37.4.499
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发表时间：
1995-10-01
期刊：
影响因子：
24.5
通讯作者：
JOYNER, MJ
中科院分区：
文献类型：
--
作者：
FORD, MJ;CAMILLERI, MJ;JOYNER, MJ
过度换气引起的症状在肠易激综合征(IBS)患者中很常见；事实上，一些人认为过度换气可能会加剧IBS的消化症状。过度换气通过中枢和外周机制改变血流动力学功能；然而，它对结肠运动功能的影响尚不清楚。因此，本研究的目的是评估过度换气对结肠张力和动力的影响以及对心血管自主神经活动的影响，并发现低碳酸血症是否是引发反应的关键。对15名健康志愿者在低碳酸血症过度换气前、中、后5分钟分别测定横结肠和乙状结肠的时相和紧张性运动、呼气末二氧化碳分压、脉搏频率和搏动变异性；在另外7名受试者中，同时评估真碳酸血症和低碳酸血症过度呼吸机的效果。低二氧化碳而不是真二氧化碳的过度换气增加了横结肠和乙状结肠区的结肠张力和时相收缩能力，并增加了脉搏频率和脉搏间期变异性。这些发现与抑制结肠的交感神经支配或低碳酸血症对结肠平滑肌的直接影响，或两者兼而有之是一致的。这些生理的肠道反应表明，结肠功能的一些变化是由大脑或自主神经控制机制改变引起的。
Symptoms attributable to hyperventilation are common among patients with the irritable bowel syndrome (IBS); indeed, some have suggested that hyperventilation may exacerbate the alimentary symptoms of IBS. Hyperventilation changes haemodynamic function through central and peripheral mechanisms; its effects on colonic motor function, however, are unknown. The aim of this study, therefore, was to assess the effects of hyperventilation on colonic tone and motility and on cardiovascular autonomic activity, and to discover if hypocapnia was critical to elicit the response. Phasic and tonic motility of the transverse and sigmoid colon, end tidal PCO2, pulse rate, and beat to beat pulse variability were assessed before, during, and after a five minute period of hypocapnic hyperventilation in 15 healthy volunteers; in seven other subjects, effects of both eucapnic and hypocapnic hyperventilation were evaluated. Hypocapnic but not eucapnic hyperventilation produced an increase in colonic tone and phasic contractility in the transverse and sigmoid regions and an increase in pulse rate and pulse interval variability. The findings are consistent with inhibition of sympathetic innervation to the colon or direct effects of hypocapnia on colonic smooth muscle, or both. These physiological gut responses suggest that some of the changes in colonic function are caused by altered brain or autonomic control mechanisms.