Lee J C, Stoll B J, Downing S E
Am J Physiol. 1977 Jul;233(1):R30-6. doi: 10.1152/ajpregu.1977.233.1.R30.
Cardiorespiratory reflex responses to laryngeal chemoreceptor stimulation were studied in 62 piglets of both sexes varying in age from 1 to 79 days. The distal trachea was cannulated to provide a free airway and the proximal end used to introduce fluids into the laryngeal area. Introduction of either water or milk produced apnea, bradycardia, and hypertension. Swab application of test fluids to the laryngeal epithelium produced similar responses. The reflex could be interrupted by flushing the laryngeal region with saline, by cutting the superior laryngeal nerves (SLN) or by anesthetizing the laryngeal epithelium with lidocaine. Electrical stimulation of SLN elicited identical responses. Respiratory inhibition by the reflex was enhanced following central depression with chloralose and overridden by administration of the respiratory stimulant, aminophylline. The relative potency of the laryngeal reflex was estimated to be equivalent to about 40% of the dose of chloralose which produced permanent respiratory arrest. It is concluded that in circumstances where respiratory drive is reduced the laryngeal inhibitory reflex is capable of caused persistent apnea and asphyxial death in the young piglet.
对62只年龄在1至79天的雌雄仔猪进行了研究，观察其对喉化学感受器刺激的心肺反射反应。在远端气管插管以提供通畅气道，近端用于向喉部区域注入液体。注入水或牛奶会导致呼吸暂停、心动过缓和高血压。用测试液擦拭喉上皮也会产生类似反应。用盐水冲洗喉部区域、切断喉上神经（SLN）或用利多卡因麻醉喉上皮可中断该反射。电刺激SLN会引发相同反应。用氯醛糖使中枢抑制后，该反射对呼吸的抑制作用增强，而给予呼吸兴奋剂氨茶碱可消除这种抑制。据估计，喉反射的相对效力相当于产生永久性呼吸停止的氯醛糖剂量的约40%。得出的结论是，在呼吸驱动力降低的情况下，喉抑制性反射能够导致幼仔猪持续性呼吸暂停和窒息死亡。
