Grogaard J, Kreuger E, Lindstrom D, Sundell H
Pediatr Res. 1986 Aug;20(8):724-9. doi: 10.1203/00006450-198608000-00005.
The response to laryngeal chemoreflex (LCR) water stimulation was compared in unanesthetized awake 4- to 10-day-old preterm and 2- to 4-wk-old term lambs before and after infusion of a beta-adrenergic agonist, terbutaline, given pre- and postcarotid body denervation (CBD). Ventilation decreased more in response to LCR stimulation post-CBD in the older lambs. CBD did not change the respiratory response to LCR stimulation in the younger lambs. LCR stimulation resulted in less bradycardia post-CBD in both groups. Terbutaline significantly attenuated the LCR response in the older lambs pre-CBD but not post-CBD. LCR respiratory response was not changed in the younger lambs when terbutaline was infused, pre- or post-CBD. Compared to wakefulness, the LCR response in preterm lambs was greater in sleep not associated with arousal. If arousal occurred, LCR response during sleep did not differ from that during wakefulness. The incidence of arousal decreased markedly after CBD, suggesting that arousal is modified by the carotid bodies. It is concluded that the carotid bodies modify the reflex response to LCR stimulation in 2- to 4-wk-old lambs. During the 1st postnatal wk, preterm lambs have a reduced carotid body function during wakefulness and, therefore, a decreased hypoxic ventilatory response and increased respiratory response to LCR stimulation. The attenuating effect of terbutaline on LCR response is partially related to mature carotid body function.
在未麻醉的清醒4至10日龄早产羔羊和2至4周龄足月羔羊中，比较了在颈动脉体去神经支配（CBD）前后输注β-肾上腺素能激动剂特布他林之前和之后，对喉化学反射（LCR）水刺激的反应。在年龄较大的羔羊中，CBD后对LCR刺激的反应中通气减少更多。CBD并未改变较年幼羔羊对LCR刺激的呼吸反应。两组中，CBD后LCR刺激导致的心动过缓均减轻。特布他林在CBD前显著减弱了年龄较大羔羊的LCR反应，但在CBD后没有。在CBD前后输注特布他林时，较年幼羔羊的LCR呼吸反应没有改变。与清醒状态相比，早产羔羊在与觉醒无关的睡眠中LCR反应更大。如果发生觉醒，睡眠期间的LCR反应与清醒期间没有差异。CBD后觉醒发生率显著降低，表明觉醒受颈动脉体调节。结论是，颈动脉体调节2至4周龄羔羊对LCR刺激的反射反应。在出生后的第一周，早产羔羊在清醒时颈动脉体功能降低，因此低氧通气反应降低，对LCR刺激的呼吸反应增加。特布他林对LCR反应的减弱作用部分与成熟的颈动脉体功能有关。
