Tallman R D, Grodins F S
J Appl Physiol Respir Environ Exerc Physiol. 1982 Dec;53(6):1386-91. doi: 10.1152/jappl.1982.53.6.1386.
It has been suggested that avian intrapulmonary CO2-sensitive receptors (IPC) may be capable of affecting ventilation in response to changes in lung CO2 load. The purpose of this study was to record IPC discharge activity in spontaneously breathing ducks when venous PCO2 was elevated or lowered from resting levels. This was accomplished using an extracorporeal venovenous blood bypass circuit, which included a 0.8-m2 silicone membrane blood oxygenator. Adult male Pekin ducks were anesthetized and tracheostomized. Single-unit activity was recorded from 42 IPC. During venous CO2 loading, there was no difference in the average IPC discharge from control despite an increase in the rate of CO2 excretion (VCO2) to twice the resting level. Venous CO2 unloading decreased VCO2 by one-half but did not significantly affect inspiratory IPC discharge and resulted in only a small increase in expiratory discharge. In contrast, inhalation of 3% CO2 greatly reduced inspiratory discharge. Reflex adjustments in tracheal flow appear to be responsible for maintaining IPC discharge at control levels when venous PCO2 changes.
有人提出，鸟类肺内二氧化碳敏感受体（IPC）可能能够根据肺内二氧化碳负荷的变化来影响通气。本研究的目的是在静脉血二氧化碳分压从静息水平升高或降低时，记录自主呼吸鸭的IPC放电活动。这是通过一个体外静脉-静脉血液旁路回路来实现的，该回路包括一个0.8平方米的硅膜血液氧合器。成年雄性北京鸭麻醉后行气管切开术。从42个IPC记录单单位活动。在静脉二氧化碳负荷期间，尽管二氧化碳排出率（VCO2）增加到静息水平的两倍，但与对照组相比，IPC平均放电没有差异。静脉二氧化碳卸载使VCO2降低一半，但对吸气IPC放电没有显著影响，仅导致呼气放电略有增加。相比之下，吸入3%二氧化碳可大大减少吸气放电。当静脉血二氧化碳分压变化时，气管流量的反射性调节似乎负责将IPC放电维持在对照水平。
