颈动脉化学感受器对二氧化碳排出量增加的反应。

Carotid chemoreceptor response to increases in CO2 output.

作者信息

Cross B A, Corfield D R, Howells K D, Stidwill R P, Newman G B, Semple S J

机构信息

Department of Medicine, University College and Middlesex School of Medicine, London, U.K.

出版信息

Respir Physiol. 1990 Jul;81(1):99-115. doi: 10.1016/0034-5687(90)90073-8.

DOI:10.1016/0034-5687(90)90073-8

PMID:2120760

Abstract

The effect on carotid chemoreceptor activity of alterations in PaCO2 oscillations produced by venous CO2 loading via the small intestines was studied in anaesthetised cats, which were paralysed and ventilated at constant frequency. Changes in PaCO2 oscillations were assessed from continuously recorded oscillations of arterial pH. Chemoreceptor activity was averaged over 20-50 pH cycles to determine the amplitude (csnd ampl) and mean level (csnd mean) of the respiratory fluctuation in discharge frequency during control and CO2 loaded periods. Two groups of 5 cats were studied. In both groups, the amplitude of the PaCO2 oscillations increased by an overall average of 74.5% (standard error, SE = 9.2) with minimal change in mean PaCO2 (average increase 0.7 mm Hg), in response to an increase in VCO2 of 77.5% (SE = 7.4). When isoxia was maintained (Group 1) csnd ampl increased by 51.3% (SE = 11.1) and csnd mean by 17.3% (SE = 7.8). In Group 2, PaO2 rose by 16.7 mm Hg (SE = 1.5) during CO2 loading and both csnd ampl and csnd mean decreased by 7.4% (SE = 9.3) and 2.3% (SE = 13.3) respectively. The results demonstrate a sensitivity of chemoreceptors to changes in VCO2 which is influenced by small changes in PaO2.

摘要

在麻醉的猫身上研究了通过小肠静脉注入二氧化碳产生的动脉血二氧化碳分压（PaCO₂）振荡变化对颈动脉化学感受器活动的影响，这些猫处于麻痹状态并以恒定频率进行通气。根据连续记录的动脉血pH振荡来评估PaCO₂振荡的变化。在对照期和二氧化碳注入期，对化学感受器活动在20 - 50个pH周期内进行平均，以确定放电频率呼吸波动的幅度（csnd ampl）和平均水平（csnd mean）。研究了两组，每组5只猫。在两组中，随着二氧化碳产生量（VCO₂）增加77.5%（标准误，SE = 7.4），PaCO₂振荡幅度总体平均增加74.5%（SE = 9.2），而平均PaCO₂变化最小（平均增加0.7 mmHg）。当维持低氧状态时（第1组），csnd ampl增加51.3%（SE = 11.1），csnd mean增加17.3%（SE = 7.8）。在第2组中，二氧化碳注入期间动脉血氧分压（PaO₂）升高16.7 mmHg（SE = 1.5），csnd ampl和csnd mean分别下降7.4%（SE = 9.3）和2.3%（SE = 13.3）。结果表明化学感受器对VCO₂变化敏感，且这种敏感性受PaO₂微小变化的影响。