UCD School of Medicine and Medical Science, University College Dublin, Dublin 4, Ireland.
Adv Exp Med Biol. 2010;669:285-7. doi: 10.1007/978-1-4419-5692-7_58.
Upper airway muscle dysfunction is implicated in obstructive sleep apnoea syndrome (OSAS), a common respiratory disorder associated with recurrent hypoxaemia. The prevalence of OSAS is higher in males than females. We tested the hypothesis that sex differences exist in the effects of intermittent hypoxia on upper airway muscle function. Adult Wistar rats were exposed to intermittent hypoxia (IH, 90 s air/90 s N(2); 5% O(2) at nadir) or sham treatment for 8 hours/day for 9 days. Following treatments, animals were killed humanely and isometric contractile properties of the sternohyoid (SH) muscle were examined at 35OC in vitro. Force-frequency relationship was determined at stimulus frequencies ranging 10-100 Hz. In male rats, SH peak force was decreased in IH-treated male rats [22.7 +/- 08. vs. 15.9 +/- 0.9 N/cm(2), sham (n = 8) vs. IH (n = 8), p < 0.001 ANOVA]. Conversely, in female rats, IH treatment had no effect on SH peak force [21.0 +/- 1.2 vs. 19.8 +/- 0.8 N/cm(2), sham (n = 8) vs. IH (n = 8), p > 0.05 ANOVA]. We conclude that IH-induced impairment of pharyngeal dilator muscle performance may contribute to OSAS.
上气道肌肉功能障碍与阻塞性睡眠呼吸暂停综合征（OSAS）有关，OSAS 是一种常见的与反复低氧血症相关的呼吸障碍，其在男性中的发病率高于女性。我们假设间歇低氧对咽肌功能的影响存在性别差异，为此进行了检验。成年 Wistar 大鼠接受间歇低氧（IH，90 s 空气/90 s N2；5% O2 时处于低谷）或假处理，每天 8 小时，共 9 天。处理后，动物被人道处死，体外在 35°C 下检查胸锁乳突肌（SH）的等长收缩特性。在 10-100 Hz 的刺激频率范围内测定力-频率关系。在雄性大鼠中，SH 峰值力在 IH 处理的雄性大鼠中降低[22.7 +/- 08. 与 15.9 +/- 0.9 N/cm(2)，假处理（n = 8）与 IH（n = 8），p < 0.001 ANOVA]。相反，在雌性大鼠中，IH 处理对 SH 峰值力没有影响[21.0 +/- 1.2 与 19.8 +/- 0.8 N/cm(2)，假处理（n = 8）与 IH（n = 8），p > 0.05 ANOVA]。我们得出结论，IH 诱导的咽扩肌功能障碍可能导致 OSAS。
