Immunohistochemical detection of atrial natriuretic peptide (ANP) in the chief cells of human carotid bodies.

The presence of atrial natriuretic peptide (ANP) was investigated in human carotid bodies using an immunoperoxidase technique. Immunoreactivity was observed in the chief cells alone, distributed in a homogeneous cytoplasmic pattern, quite different from the granular cytoplasmic pattern known for atrial myocytes. We conclude that ANP is present in human carotid bodies, where it may be synthesized or internalized by the chief cells.