Department of Anesthesiology, Tokyo Metropolitan Ohtsuka Hospital, Tokyo, Japan.
Anaesthesia. 2014 May;69(5):468-75. doi: 10.1111/anae.12590. Epub 2014 Mar 7.
Doxapram is the only dedicated respiratory stimulant used to aid recovery of breathing after major surgery. Doxapram acts on peripheral chemoreceptors and although the central action of doxapram has been suggested, its detailed neuronal mechanism is unknown. We assessed doxapram-induced changes in spontaneous cervical nerve (C4) inspiratory activity and the firing of action potentials in pre-inspiratory and inspiratory neurones in the medulla. Experiments were performed in neonatal rat brainstem-spinal cord preparations, which can produce respiratory rhythm for several hours under in vitro conditions. Doxapram application (for 15 min) increased the frequency and amplitude of C4 activity dose-dependently. Doxapram induced changes in the electrophysiological properties of pre-inspiratory and inspiratory neurones. Our results suggest that respiratory activity enhancement was likely to be induced via effects on the potassium channels of pre-inspiratory and inspiratory neurones and indicate the central actions of doxapram.
多沙普仑是唯一一种专门用于辅助大手术后恢复呼吸的呼吸兴奋剂。多沙普仑作用于外周化学感受器，尽管已经提出了多沙普仑的中枢作用，但它的详细神经元机制尚不清楚。我们评估了多沙普仑诱导的自发性颈神经（C4）吸气活动的变化以及延髓中吸气前和吸气神经元中动作电位的放电。实验在新生大鼠脑干-脊髓制备物中进行，在体外条件下，该制备物可以产生数小时的呼吸节律。多沙普仑（15 分钟）的应用剂量依赖性地增加了 C4 活动的频率和幅度。多沙普仑改变了吸气前和吸气神经元的电生理特性。我们的结果表明，呼吸活动的增强可能是通过对吸气前和吸气神经元的钾通道的作用而引起的，这表明了多沙普仑的中枢作用。
