Role of excitatory amino acids in the mediation of tracheobronchial cough induced by citric acid inhalation in the rabbit
Role of excitatory amino acids in the mediation of tracheobronchial cough induced by citric acid inhalation in the rabbit
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DOI：
10.1016/j.brainresbull.2009.05.022
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发表时间：
2009-08-28
影响因子：
3.8
通讯作者：
Pantaleo, Tito
中科院分区：
文献类型：
--
作者：
Mutolo, Donatella;Bongianni, Fulvia;Pantaleo, Tito
我们研究了位于孤束核（cNTS）和尾侧腹侧呼吸组（cVRG）的尾侧部分内的离子型谷氨酸受体在戊巴比妥麻醉下自发呼吸家兔吸入柠檬酸诱发咳嗽的介导中的作用。进行双侧显微注射（30-50 nl）10 mM CNQX和10 mM D-AP 5以分别阻断非NMDA和NMDA受体。还尝试研究cVRG内的离子型谷氨酸受体阻断剂对鼻粘膜的机械刺激诱导的打喷嚏的影响。阻断cNTS内的非NMDA受体可消除咳嗽和相关的呼吸急促反应，而阻断NMDA受体仅减少咳嗽反应。阻断cVRG内的非NMDA受体总是消除自发性节律性腹部活动以及咳嗽和相关的呼吸急促反应;阻断NMDA受体仅减少自发性节律性腹部活动和咳嗽。对于打喷嚏，阻断cVRG内的非NMDA受体抑制呼气推力而不影响吸气准备爆发，而阻断NMDA受体仅强烈减弱呼气推力。这项研究是第一个提供证据，离子型谷氨酸受体，特别是非NMDA受体，参与柠檬酸吸入诱导的咳嗽的调解，并建议柠檬酸激活咳嗽相关的传入终止在cNTS。目前的数据也证实了cVRG参与整个咳嗽运动模式的产生的概念，但似乎仅仅代表了打喷嚏的呼气输出系统。(C)2009爱思唯尔公司All rights reserved.
We investigated the role of ionotropic glutamate receptors located within the caudal portions of the nucleus tractus solitarii (cNTS) and the caudal ventral respiratory group (cVRG) in the mediation of coughing evoked by citric acid inhalation in spontaneously breathing rabbits under pentobarbitone anaesthesia. Bilateral microinjections (30-50 nl) of 10 mM CNQX and 10 mM D-AP5 were performed to block non-NMDA and NMDA receptors, respectively. An attempt was also made to investigate the effects of ionotropic glutamate receptor blockade within the cVRG on sneezing induced by mechanical stimulation of the nasal mucosa. Blockade of non-NMDA receptors within the cNTS abolished coughing and associated tachypneic responses, while blockade of NMDA receptors only reduced cough responses. Blockade of non-NMDA receptors within the cVRG always abolished spontaneous rhythmic abdominal activity as well as coughing and associated tachypneic responses; blockade of NMDA receptors only reduced spontaneous rhythmic abdominal activity and coughing. As to sneezing, blockade of non-NMDA receptors within the cVRG suppressed the expiratory thrusts without affecting the inspiratory preparatory bursts, while blockade of NMDA receptors only strongly attenuated the expiratory thrusts. This study is the first to provide evidence that ionotropic glutamate receptors, and especially non-NMDA receptors, are involved in the mediation of coughing induced by citric acid inhalation and to suggest that citric acid-activated cough-related afferents terminate within the cNTS. Present data also corroborate the notion that the cVRG is involved in the generation of the whole cough motor pattern, but seems to represent merely an expiratory output system for sneezing. (C) 2009 Elsevier Inc. All rights reserved.