Forster H V, Pan L G
Department of Physiology, Medical College of Wisconsin, Milwaukee.
Med Sci Sports Exerc. 1994 Mar;26(3):328-36.
Our objective was to gain insight into the role of the carotid chemoreceptors (CC) in the exercise hyperpnea. Humans and ponies were studied at rest and during submaximal exercise breathing room air. In healthy humans, alveolar ventilation (VA) was tightly matched to CO2 production (CO2) resulting in PaCO2 deviating during exercise less than 1-2 mm Hg from rest. In contrast, ponies' VA increased proportionately more than VCO2 during exercise resulting in a workload dependent hypocapnia. Attenuating CC activity through hyperoxia had no effect on exercise PaCO2 of humans but hyperoxia accentuated the exercise hypocapnia of ponies. Similarly, CC denervation accentuated the exercise hypocapnia of ponies. Healthy humans were also studied while external airway resistance was increased, which, while breathing room air, resulted in a workload dependent hypercapnia, and this hypercapnia was accentuated by hyperoxia. Finally, a majority of asthmatic humans studied were hypercapnic during exercise while breathing room air and the hypercapnia was accentuated by hyperoxia. We conclude that the CC do not provide a primary drive for the exercise hyperpnea but they "fine tune" VA to minimize disruptions of arterial blood gases. In healthy humans, attenuating CC activity has no effect on PaCO2 because the primary VA drive is closely matched to VCO2.
我们的目的是深入了解颈动脉化学感受器（CC）在运动性通气过度中的作用。在静息状态和次最大运动时呼吸室内空气的情况下，对人类和小马进行了研究。在健康人类中，肺泡通气量（VA）与二氧化碳产生量（CO2）紧密匹配，导致运动期间动脉血二氧化碳分压（PaCO2）与静息时相比偏离小于1 - 2 mmHg。相比之下，小马在运动期间VA的增加比例大于二氧化碳排出量（VCO2），导致出现与工作量相关的低碳酸血症。通过高氧减弱CC活性对人类运动时的PaCO2没有影响，但高氧会加重小马运动时的低碳酸血症。同样，CC去神经支配会加重小马运动时的低碳酸血症。在增加外部气道阻力的情况下，也对健康人类进行了研究，在呼吸室内空气时，这会导致与工作量相关的高碳酸血症，并且高氧会加重这种高碳酸血症。最后，大多数接受研究的哮喘患者在运动时呼吸室内空气时会出现高碳酸血症，并且高氧会加重这种高碳酸血症。我们得出结论，CC并非运动性通气过度的主要驱动因素，但它们会“微调”VA，以尽量减少动脉血气的干扰。在健康人类中，减弱CC活性对PaCO2没有影响，因为主要的VA驱动力与VCO2紧密匹配。
