Pulmonary endocrine cells in native Peruvian guinea-pigs at low and high altitude.

The role of pulmonary endocrine cells is unclear, but those which are aggregated into innervated clusters are probably chemoreceptors, responding to hypoxia in the airways, whereas solitary endocrine cells are probably quite different in their function. There were significantly more clusters of endocrine cells in the lungs of a group of 10 indigenous Peruvian guinea-pigs considered to be adapted to high altitude, in comparison with controls from sea-level, whereas there was no difference in the number of solitary cells. It is concluded that, whereas the clusters are indeed responding to and affected by hypoxia, the solitary cells are not, and play a distinct and possibly trophic role in the lung.