中文摘要：

目的：观察低压低氧诱导大鼠阻塞性睡眠呼吸暂停综合征（obstructive sleep apnea syndrome，OSAS）后大鼠咽部肌肉结构和功能的变化，探讨咽腔重建以及OSAS形成可能的生物力学机制。方法：24只成年SD大鼠，雌雄各半，分为低压低氧诱导雄鼠（A）组、对照雄鼠（B）组、低压低氧诱导雌鼠（C）组、对照雌鼠（D）组。共4组（n=6）。低压低氧诱导组（A、C）大鼠每天6h，连续22d进入低压氧仓（压力53．9kPa，氧浓度10％～11．2％），对照组（B、D）不接受低压低氧诱导。低压低氧诱导完成后（实验第23天）处死全部大鼠，行咽肌环张开角、咽肌环内径、咽部组织病理检查。结果：A、B、C、D组大鼠咽肌环张开角分别为：（55±24）°、（15±8）°、（38±20）°、（35±15）°；内径分别为：（0．4±0．2）、（0．2±0．1）、（0．3±0．1）、（0．3±0．1）cm。A组咽肌环张开角、内径较B、C、D组明显增大（P〈0．05），C、D组间无明显区别。光镜下可见：A组咽肌肌纤维肥大、排列紊乱，横纹模糊不清，上皮下组织充血水肿、炎症细胞浸润；C组可见局部横纹不清；B、D组肌纤维排列整齐，上皮下组织无炎症。电镜下可见：A组肌原纤维结构紊乱、肌丝溶解，部分z带呈锯齿状排列、有断裂消失，肌质网囊状扩张、空泡样变性，肌细胞核轻度固缩；C组可见局部肌丝溶解。结论：22d间歇性低压低氧诱导可能通过改变咽肌结构和功能，重建咽腔，从而诱导大鼠OSAS形成。

英文摘要：

Objective：To observe the changes of structure and function of pharyngeal muscle in SD rats with altitude hypoxia induced obstructive sleep apnea syndrome （OSAS） , in an attempt to investigate the remodeling of pharyngeal space and the possible biomechanical mechanism of OSAS. Methods： Twenty-four SD rats（ 12 male and 12 female） were randomly assigned to 4 groups with 6 rats in each group. Rats in group A and B were male and those in group C and D were female. Rats in group A and C were placed in altitude chamber and treated with altitude hypoxia 6 h per day for 22 days. The pressure in the chamber was 53.9 kPa with an oxygen concentration of 10.0%-11.2%. Rats in group B and D, serving as controls, received no treatment. All rats were sacrificed on the 23^rd day. The open-angle and the inside diameter of rats＇ pharyngeal-ring and the pathology of pharyngeal tissues were examined in all rats. Results： The open-angles of rats＇ pharyngeal-ring of group A, B, C and D were （55±24）°, （ 15±8）°, （38±20）°, and （35 ± 15）°, respectively; and the inside diameters of the pharyngeal-ring（cm） were 0.4±0.2, 0.2±0.1, 0.3±0.1, and 0.3±0. 1, respectively. The open-angle and the inside diameter of rats＇ pharyngeal-ring in group A were significantly higher （P〈0.05） than those of group B, C, and D, with no significant difference found between group C and D. Microscopic findings showed that, compared with group B, the muscle fibers of group A were fatter and were arranged disorderly, with unclear transverse striation, dropsical and congestive subcutaneous tissues infiltrated with inflammatory cells. Local unclear transverse striation of muscle fiber was seen in group C; the muscle fibers in group B and D were orderly arranged and no inflammatory cells were seen subcutaneously, Electron microscope showed disarranged muscle fibers with dissolved myofilament, disturbance and disappearance of the Z line in part of muscle fibers, expanded sarcoplasmic reticulum, and slightly condensed