R. Gelfand

Significance of peripheral chemoreceptor response and adaptation in the regulation of breathing.

The objective of this presentation is to focus attention on some neglected aspects of peripheral chemoreflexes in the regulation of breathing. Since the work of Gesell and White1 the phase dependent effect of carotid chemoreceptor stimulation on volume and duration of breaths in resting animals has been firmly established by Black and Torrance2 and Eldridge3, 4 In recent years these observations on the stimulating effect dominated the literature on peripheral chemoreflex control of breathing. But stimulation is not the only aspect of this reflex. Withdrawal of stimulation is a natural occurrence. Waxing and waning of peripheral chemoreceptor activity occurs with respiration5 and blood flow (unpublished observation). A phase relationship between these aspects and respiratory oscillations is expected to determine in part the extent of stimulation and effects of withdrawal. We examined simultaneously the effect of withdrawal of arterial stimulus on carotid chemoreceptor activity and ventilation and related ventilation to carotid chemoreceptor activity. These results emphasize the importance of overall dynamic aspects of peripheral chemoreceptor activity on single breaths as well as on minute ventilation.