Tsuchiya Y, Hosokawa T, Kasuya Y
Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan.
Jpn J Pharmacol. 1989 Aug;50(4):403-10. doi: 10.1254/jjp.50.403.
In this study, the effects of carotid chemoreceptors on reflex tracheal constriction were investigated in anesthetized, paralyzed, and artificially ventilated mongrel dogs. Reflex tracheal constriction was measured as changes in the intratracheal pressure of an air-filled balloon introduced into the rostral side of the transected trachea. A hypoxic condition was produced by ventilating the dog with 12% O2-88% N2. The reflex tracheal constriction induced by histamine inhalation to the bronchial side was reduced by section of the bilateral sinus nerves. The hypoxic condition significantly potentiated the reflex tracheal constriction induced by histamine inhalation. The potentiated reflex tracheal constriction during hypoxia was abolished by section of the bilateral sinus nerves. The afferent electrical stimulation to the central cut end of the vagus nerve caused a reflex tracheal constriction. The reflex tracheal constriction was significantly potentiated by hypoxia, and the potentiating response was abolished by section of the bilateral sinus nerves. The infusion of NaCN into the bilateral carotid arteries significantly potentiated the reflex tracheal constriction. The NaCN-induced potentiating effect was abolished by section of the bilateral sinus nerves. These results suggest that hypoxia potentiates the vagal reflex-induced tracheal constriction and that the hypoxia-induced potentiating effects may be mediated by carotid chemoreceptors.
在本研究中，在麻醉、麻痹并进行人工通气的杂种犬身上，研究了颈动脉化学感受器对反射性气管收缩的影响。反射性气管收缩通过插入到横断气管头侧的充气球囊的气管内压力变化来测量。通过用12% O₂-88% N₂对犬进行通气来制造低氧状态。吸入组胺至支气管侧所诱发的反射性气管收缩，在切断双侧窦神经后减弱。低氧状态显著增强了吸入组胺所诱发的反射性气管收缩。低氧期间增强的反射性气管收缩在切断双侧窦神经后被消除。对迷走神经中枢端切断处进行传入电刺激会引起反射性气管收缩。反射性气管收缩在低氧状态下显著增强，且增强反应在切断双侧窦神经后被消除。向双侧颈动脉内注入NaCN显著增强了反射性气管收缩。NaCN诱导的增强效应在切断双侧窦神经后被消除。这些结果表明，低氧增强了迷走神经反射诱发的气管收缩，且低氧诱导的增强效应可能由颈动脉化学感受器介导。
