家兔疑核内P2X受体在急性低氧中的作用

目的研究疑核(nucleus ambiguous，NA)处P2X受体在急性低氧中的作用。方法实验采用电生理和微量注射相结合的方法，以膈神经放电为观察指标，观察呼吸变化。通过吸入10％氧气(10％O₂，90％N₂)引导出低氧外周化学感受性反射。在NA处分别微量注射P2X受体的激动剂三磷酸腺苷（ATP）和阻断剂磷酸吡哆醛（PPADS），观察这些药物对急性低氧呼吸的影响。结果 吸入低氧混合气后，动物呼吸加深加快；在NA处微量注射ATP增强了急性低氧呼吸频率，微量注射PPADS部分阻断了ATP对低氧通气的兴奋效应。结论NA处P2X受体对急性低氧通气反应具有一定的调节作用。

Effects of P2X receptors within the nucleus ambiguous on hypoxian respiration in rabbits

To investigate the effects of P2X receptor in the nucleus ambiguous (NA) on acute hypoxic ventilation. Methods Experiments were performed on anesthetized, immobilized and artificially ventilated rabbits. The peripheral chemo-reflex to hypoxia was elicited by ventilating the animals with 10％O₂ balance 90％N₂. Changes in the peak amplitude and frequency of integrated phrenic nerve discharge were recorded. The ventilatory responses of the peripheral chemo reflex following microinjection within the NA of either P2X receptor agonist adenosine triphosphate (ATP) or antagonist pyridoxal-5′-phosphate-6-azo-phenyl-2, 4-disulfonate (PPADS) were observed. ResultsExcitation of the phrenic never discharge was induced by ventilating the animals with hypoxic mixed gases. Microinjection of ATP in NA increased the frequency of acute hypoxic respiration, whereas microinjection of PPADS partially blocked the respiratory effects of ATP microinjected into NA. ConclusionThe present results suggested that ATP acting via the P2X receptor in the NA may be involved in the respiration control of the acute hypoxic ventilatory response.