Experimental studies of pharyngeal dilating reflex and airway patency in rabbits

背景：上呼吸道反射包括保护气道的反射和扩张气道的反射。后一种反射，即咽扩张反射对气道负压（NPAR），在维持气道通畅中起重要作用，尽管参与NPAR的外周受体尚未明确。方法：通过观察兔咽舌肌（GG）的活动，观察咽黏膜表面麻醉对NPAR的影响。硫喷妥钠麻醉后，在每只兔的气管上切开2个切口。通过这些切口，一根与麻醉回路相连的管子插入肺部，另一根与吸入器相连的管子进入咽部。在1%利多卡因表面麻醉和不表面麻醉的情况下，记录负压对GG脊髓图的影响。结果：无表面麻醉的负压暴露组GG放电增加，表面麻醉组GG放电明显减少。结论：NPAR的外周受体位于咽部粘膜。

Background : Upper airway reflexes include a reflex protecting the airway as well as another dilating the airway. The latter reflex, the pharyngeal dilator reflex to negative airway pressure (NPAR), plays an important role in maintaining airway patency, although the peripheral receptors involved in NPAR have not been specified.Methods : The effects of surface anesthesia of the pharyngeal mucous membrane on NPAR were evaluated by observing activity of the musculus genioglossus (GG) in rabbits. Following anesthesia with thiopental, two incisions were made on the trachea of each rabbit. Through these incisions, a tube connected to the anesthetic circuit was inserted into the lung and another tube connected to an aspirator into the pharynx. Effects of negative pressure on the myelogram of the GG were recorded with and without surface anesthesia with 1% lidocaine.Results : Electric discharge from the GG was increased in the sessions with exposure to negative pressure without surface anesthesia, but was significantly decreased in those with surface anesthesia.Conclusion : These findings suggest that the peripheral receptors of NPAR are located in the pharyngeal mucous membrane.