Fagenholz S A, Lee J C, Downing S E
Am J Physiol. 1979 Jul;237(1):R10-4. doi: 10.1152/ajpregu.1979.237.1.R10.
Effects of peripheral arterial chemodernervation on laryngeal reflex-induced apnea were studied in 18 piglets of either sex varying in age from 4 to 63 days. The distal trachea was cannulated with a cuffed endotracheal tube to secure a free airway and permit ventilatory measurements with a pneumotachograph. The proximal trachea was used to introduce fluids into the larynx. Water elicited apnea, bradycardia, and arterial hypertension, whereas saline caused only transient disturbances. Electrical stimulation of the superior laryngeal nerves reproduced, and conduction anesthesia ablated, the effects of water in the larynx. Carotid body contribution to respiratory drive was assessed by the ventilatory responses to increased (100%) and decreased (10%) anbient oxygen concentration. These indicated significant peripheral chemoreceptor ventilatory activity from birth with little further change in the neonatal period. Ventilatory responses to oxygen were ablated by carotid chemodenervation, but there was no change in the duration of laryngeal reflex apnea. We conclude that attenuation of laryngeal-induced apnea during postnatal development is independent of peripheral chemoreceptor activity. Our findings may have relevance to the clinical problem of sudden infant death syndrome, in which carotid body abnormalities have recently been described.
在18只年龄从4天到63天不等的雌雄仔猪中，研究了外周动脉化学去神经支配对喉反射性呼吸暂停的影响。用带套囊的气管内导管插入远端气管，以确保气道通畅，并允许使用呼吸流速计进行通气测量。近端气管用于向喉部注入液体。水可引发呼吸暂停、心动过缓和动脉高血压，而盐水仅引起短暂干扰。电刺激喉上神经可重现水在喉部的作用，传导麻醉可消除这种作用。通过对环境氧浓度升高（100%）和降低（10%）的通气反应来评估颈动脉体对呼吸驱动的贡献。这些表明从出生起外周化学感受器就有显著的通气活动，在新生儿期几乎没有进一步变化。颈动脉化学去神经支配可消除对氧的通气反应，但喉反射性呼吸暂停的持续时间没有变化。我们得出结论，出生后发育过程中喉诱发的呼吸暂停减弱与外周化学感受器活动无关。我们的发现可能与婴儿猝死综合征的临床问题相关，最近已描述了该综合征中颈动脉体异常的情况。
