Malhotra Atul, Pillar Giora, Fogel Robert B, Edwards Jill K, Ayas Najib, Akahoshi Toshiki, Hess Dean, White David P
Sleep Medicine Division and Pulmonary and Critical Care Division, Department of Medicine, Brigham and Women's Hospital and Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Am J Respir Crit Care Med. 2002 Jan 1;165(1):71-7. doi: 10.1164/ajrccm.165.1.2011065.
Pharyngeal dilator muscles are clearly important in the pathogenesis of obstructive sleep apnea syndrome. Substantial data support the role of local mechanisms in mediating pharyngeal dilator muscle activation in normal humans during wakefulness. Using a recently reported iron lung ventilation model, we sought to determine the stimuli modulating genioglossus activity, dissociating the influences of pharyngeal negative pressure, from inspiratory airflow, resistance, and CO(2). To achieve this aim, we used two gas densities at several levels of end-tidal CO(2) and a number of intrapharyngeal negative pressures. The correlations between genioglossus electromyography (GGEMG) and epiglottic pressure across a breath remained robust under all conditions (R values range from 0.71 +/- 0.07 to 0.83 +/- 0.05). In addition, there was no significant change in the slope of this relationship despite variable gas density or CO(2) levels. Although flow also showed strong correlations with genioglossus activity, there was a significant change in the slope of the GGEMG/flow relationship with altered gas density. For the group averages across conditions (between breath analysis), the correlation with GGEMG was robust for negative pressure (R(2) = 0.98) and less strong for other variables such as flow and resistance. These data suggest that independent of central pattern generator activity, intrapharyngeal negative pressure itself modulates genioglossus activity both within breaths and between breaths.
咽扩张肌在阻塞性睡眠呼吸暂停综合征的发病机制中显然起着重要作用。大量数据支持局部机制在清醒状态下介导正常人类咽扩张肌激活中的作用。利用最近报道的铁肺通气模型，我们试图确定调节颏舌肌活动的刺激因素，区分咽负压、吸气气流、阻力和二氧化碳的影响。为实现这一目标，我们在几个呼气末二氧化碳水平下使用了两种气体密度以及多种咽内负压。在所有条件下，一次呼吸过程中颏舌肌肌电图（GGEMG）与会厌压力之间的相关性均保持稳定（R值范围为0.71±0.07至0.83±0.05）。此外，尽管气体密度或二氧化碳水平有所变化，但这种关系的斜率并无显著改变。虽然气流也与颏舌肌活动显示出很强的相关性，但随着气体密度的改变，GGEMG/气流关系的斜率发生了显著变化。对于所有条件下的组平均值（呼吸间分析），与GGEMG的相关性在负压方面很强（R² = 0.98），而在气流和阻力等其他变量方面则较弱。这些数据表明，独立于中枢模式发生器活动，咽内负压本身在呼吸内和呼吸间均可调节颏舌肌活动。
