Haxhiu M A, van Lunteren E, Mitra J, Cherniack N S
Department of Medicine, Case Western Reserve University, Cleveland, OH 44106.
Respir Physiol. 1987 Nov;70(2):183-93. doi: 10.1016/0034-5687(87)90049-1.
The steady state and transient effects of hyperoxic hypercapnia on the electromyographic activities of the genioglossus (GG), posterior cricoarytenoid (PCA), and diaphragm (D) were studied in cats instrumented with chronically implanted electrodes during non-rapid eye movement sleep. Hypercapnia (inhalation of 3.4 and 7.4% CO2 in O2) increased the phasic electrical activity occurring during inspiration of all three muscles. Activities of the PCA and D increased in a parallel fashion with increasing CO2. The GG responded to steady state CO2 inhalation alinearly, with larger increases in activity occurring when CO2 was raised from 3.4 to 7.4% than when CO2 was increased from 0 to 3.4%. When gas mixtures containing CO2 were given, the GG reached its new steady state level more slowly than the D or PCA, and when CO2 was rapidly removed from the inspired gas mixture, the GG attained its steady state sooner than the D. These results suggest that in sleeping cats, hypercapnia does not affect either transient or steady state responses of the GG in the same way as the D or the PCA. These differences seem to be explained largely by different threshold characteristics of hypoglossal and phrenic neurons.
在非快速眼动睡眠期间，对长期植入电极的猫进行研究，以探讨高氧高碳酸血症对颏舌肌（GG）、环杓后肌（PCA）和膈肌（D）肌电图活动的稳态和瞬态影响。高碳酸血症（吸入含3.4%和7.4%二氧化碳的氧气）增加了所有三块肌肉吸气时出现的阶段性电活动。PCA和D的活动随着二氧化碳浓度的增加而平行增加。GG对稳态二氧化碳吸入的反应呈非线性，当二氧化碳从3.4%升至7.4%时，活动增加幅度大于从0升至3.4%时。当给予含二氧化碳的混合气体时，GG达到新稳态水平的速度比D或PCA慢，而当从吸入气体混合物中迅速去除二氧化碳时，GG比D更快达到稳态。这些结果表明，在睡眠猫中，高碳酸血症对GG的瞬态或稳态反应的影响与D或PCA不同。这些差异似乎主要由舌下神经和膈神经神经元的不同阈值特性来解释。
