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在游离灌流的颈动脉体窦神经标本，观察了ＰＯ２降低、ＰＣＯ２增加和ｐＨ降低对化学感受性单位放电的影响。共记录了３２个有自发放电的化学感受性单位对三种自然刺激的反应。所得结果如下：（１）只对ＰＯ２降低有反应的化学感受性单位（对ＰＣＯ２增加及ｐＨ降低均无反应）有１０例（占总数的３１％），对三种自然刺激均有反应的化学感受性单位有９例（占２８％），对ＰＯ２降低和ＰＣＯ２增加有反应的化学感受性单位有９例（占２８％），对ＰＯ２降低和ｐＨ降低两种刺激有反应的化学感受性单位有３例（占９％），另有一例只对ｐＨ降低有反应。（２）不同的自然刺激对化学感受性单位放电频率影响不一致。ＰＯ２降低使放电频率增加最多，其次是ＰＣＯ２增加，作用最弱的是ｐＨ降低。根据以上结果，似可认为，在颈动脉体中存在着不同生理特性的化学感受性单位，它们对ＰＯ２，ＰＣＯ２或ｐＨ有不同的敏感性。
In the free perfused carotid sinuses, we observed the effects of decreased PO2, increased PCO2, and decreased pH on chemosensitive discharges. A total of 32 spontaneous discharge chemosensitive units were recorded in response to three natural stimuli. The results obtained were as follows: (1) Chemotherapeutic units that respond only to PO2 lowering (no response to PCO2 increase and pH drop) were 10 (31% of the total), chemosensitivity to all three natural stimuli There were 9 patients (28%), 9 chemotherapeutic units (28%) responding to a decrease in PO2 and PCO2 increase, 3 chemosensitivity units responding to both PO2 lowering and pH lowering stimuli Accounting for 9%), while another only responded to pH drop. (2) Different natural stimuli have different effects on the discharge frequency of chemosensitive units. The decrease of PO2 increases the discharge frequency most, followed by the increase of PCO2, and the weakest part is the decrease of pH. Based on the above results, it seems that in the carotid body there are different physiological characteristics of the chemosensitive units, they PO2, PCO2 or pH have different sensitivities.