ABSTRACT
This review is a comparative discussion of the most important aspects of two oxygen-sensitive chemoreceptor types: the arterial carotid bodies and the pulmonary neuroepithelial bodies. The two types are contrasted with regard to physiology and histochemistry, nerve terminals and synaptic junctions, neurotransmitters and membrane receptors, oxygen sensors and membrane channels, and embryology and development. Because the carotid bodies are compact, isolated organs, while the neuroepithelial bodies are diffuse and deeply integrated in the lungs, different experimental approaches have had to be applied to each of them. Nevertheless, it has become clear that the two function in very similar ways, in spite of their very different embryological background, the apparently different nature of their membrane oxygen sensors, and their orientation towards different body compartments. Just about the only functional aspect in which they fundamentally differ would appear to be the time course of their development: neuroepithelial bodies seem to develop in advance of the carotid bodies. Further progress in our understanding of both carotid and neuroepithelial bodies might greatly profit from a comparative experimental approach.
