EFFECT OF CODEINE ON THE INSPIRATORY AND EXPIRATORY BURST PATTERN DURING FICTIVE COUGH IN CATS
EFFECT OF CODEINE ON THE INSPIRATORY AND EXPIRATORY BURST PATTERN DURING FICTIVE COUGH IN CATS
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DOI：
10.1016/0006-8993(94)90792-7
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发表时间：
1994-10-31
期刊：
影响因子：
2.9
通讯作者：
DEGENNARO, FC
中科院分区：
文献类型：
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作者：
BOLSER, DC;DEGENNARO, FC
实验研究了阿片类药物可待因对咳嗽运动模式不同成分的影响。中脑去大脑的猫被麻醉，并通过由膈神经图触发的泵进行人工呼吸。记录吸气(膈)和呼气(颅、髂腹下)神经图。通过机械刺激胸腔内气管产生假性咳嗽。可待因(0.03-1.0 mg.Kg(-1)，静脉注射)减少咳嗽频率(每次刺激试验的平均咳嗽次数)、呼气爆发幅度和吸气爆发幅度，并呈剂量依赖关系。在这两个参数中，可待因对咳嗽频率和呼气幅度的最大减少率为80-90%。但可待因更有效地减少咳嗽次数(ED(50)=0.1 mg。Kg(-1))，呼气爆发幅度(ED(50)=0.35 mg。Kg(-1))。可待因引起的吸气猝发幅度的最大降幅约为40%。假性咳嗽时，膈肌波幅与颅骨髂腹下爆发波幅呈直线正相关(r=0.82P<；0.001)。可待因破坏了吸气和呼气爆发幅度之间的这种关系，从而破坏了假想咳嗽时的运动模式。我们的结论是：(A)咳嗽中枢模式发生器在功能上分为咳嗽频率发生器、呼气爆发幅度发生器和吸气爆发幅度发生器，它们对可待因具有不同的敏感性。(B)咳嗽时存在一种与吸气和呼气运动神经元的中枢驱动的相对大小相匹配的可待因敏感的神经机制。
Experiments were conducted to study the effect of the opioid, codeine, on different components of the cough motor pattern. Midcollicular decerebrate cats were paralyzed and artificially ventilated by a pump triggered by the phrenic neurogram. Inspiratory (phrenic) and expiratory (cranial iliohypogastric) neurograms were recorded. Fictive cough was produced by mechanical stimuli applied to the intrathoracic trachea. Codeine (0.03-1.0 mg . kg(-1), i.v.) decreased cough frequency (average number of coughs per stimulus trial), expiratory burst amplitude, and inspiratory burst amplitude in a dose-dependent manner. The maximum reduction in cough frequency and expiratory amplitude produced by codeine was 80-90% for both parameters. However, codeine was more potent in reducing cough frequency (ED(50) = 0.1 mg . kg(-1)) than expiratory burst amplitude (ED(50) = 0.35 mg . kg(-1)). The maximum observed reduction of inspiratory burst amplitude elicited by codeine was approximately 40%. There was a positive linear relationship between phrenic and cranial iliohypogastric burst amplitudes during fictive cough (r = 0.82, P < 0.001). Codeine destabilized the motor pattern during fictive cough by disrupting this relationship between inspiratory and expiratory burst amplitudes. We conclude: (a) the central pattern generator for cough is functionally organized into a cough frequency generator, an expiratory burst amplitude generator and an inspiratory burst amplitude generator, each of which have different sensitivities to codeine (b) there exists a specific codeine-sensitive neural mechanism matching the relative magnitude of central drive to inspiratory and expiratory motoneurons during cough.