Davies A, Sant'Ambrogio F B, Sant'Ambrogio G
Respir Physiol. 1980 Aug;41(2):211-6. doi: 10.1016/0034-5687(80)90053-5.
We recorded the e.m.g. activity of the diaphragm and of an abdominal muscle (ext. oblique) and the respiratory volume in anesthetized rabbits challenged with head-up tilting and positive pressure breathing (PPB). Both maneuvers determined an inhibition of inspiratory activity and an activation of abdominal muscles, the latter being especially marked with tilting. After cervical vagotomy neither the inspiratory inhibition nor the abdominal recruitment was present during tilting and PPB and the FRC increase was more pronounced. Sulphur dioxide was given in the inspired air (200 ppm) to selectively block the slowly adapting mechanoreceptors. Such blockade was indicated by the absence of the Hering-Breuer inflation reflex. The permanence of other respiratory reflexes was shown by a parodoxical response to inflation and by a still evident response to deflation. With SO2 block, both tilting and PPB did not elicit either the inspiratory inhibition or the abdominal muscles activation, leading to an FRC shift similar to that observed after vagotomy. We conclude that the slowly adapting mechanoreceptors subserve a reflex mechanism relevant in controlling FRC.
我们记录了麻醉兔在进行头高位倾斜和正压通气（PPB）时膈肌和一块腹部肌肉（腹外斜肌）的肌电图活动以及呼吸量。这两种操作均导致吸气活动受到抑制且腹部肌肉被激活，后者在倾斜时尤为明显。颈迷走神经切断术后，在倾斜和PPB过程中既没有吸气抑制也没有腹部肌肉的募集，功能残气量（FRC）的增加更为显著。在吸入气体中给予二氧化硫（200 ppm）以选择性阻断慢适应性机械感受器。赫林 - 布雷尔充气反射消失表明了这种阻断。对充气的反常反应以及对放气仍明显的反应表明其他呼吸反射仍然存在。在二氧化硫阻断的情况下，倾斜和PPB均未引起吸气抑制或腹部肌肉激活，导致FRC的变化类似于迷走神经切断术后观察到的情况。我们得出结论，慢适应性机械感受器参与了一种与控制FRC相关的反射机制。
