迷走神经紧张性传入在家兔急性窒息时膈神经放电反应中的作用

THE ROLE OF TONIC VAGAL AFFERENT IN PHRENIC DISCHARGE RESPONSE DURING ASPHYXIA IN RABBIT

研究了30只麻醉、肌肉松驰和人工通气家兔颈迷走神经切断前后急性窒息时膈神经放电反应的差异.切断迷走神经后窒息潜伏期延长,兴奋期、抑制期和耐受窒息时间缩短(P<0.01).积分膈神经放电幅度兴奋期和抑制期明显降低(P<0.01).兴奋期频率增值显著减少(P<0.01).恢复胡出现中枢呼吸活动时间延长.这些差别与动脉血气变化,切断喉上神经、喉返神经和腹迷走神经无关(P>0.05).提示肺迷走神经紧张性传入能加剧窒息膈神经放电反应.

We studied the difference of phrenic discharge response to acute asphyxia between pre- and post-vagotomy in anesthetized, paralyzed and artificially ventilated rabbits. Bilateral cervical vagotomy prolonged the latent period (P<0.01) but reduced the excitatory and inhibitory periods (EP, IP) and the duration enduring asphyxia during asphyxia (P<0.01). The amplitude at EP and IP and the increasing value of frequency at EP significantly decreased after vagotomy (P<0.01). The first central respiratory activity was considerably delayed (P<0.01) and its rhythm was mostly regular at recovery period after vagotomy. The differences did not relate to the change in arterial blood gases and the cutting of superior laryngeal, recurrent laryngeal and abbominal vagal nerves. The results demonstrate that the tonic vagal afferent activity can markedly increase the phrenic discharge response to asphyxia.