Neuropeptide-Y-immunoreactive chief cells in the carotid body of young rats.

The immunolight- and electron-microscopic study revealed neuropeptide Y (NPY) immunoreactivity in the chief cells and a few nerve fibers of the carotid body of young rats. NPY-immunoreactive chief cells were often seen as a single cell or a group of a few chief cells in the carotid body of young rats. The immunoreaction deposits were mainly seen in the dense-cored vesicles and diffusely in the cytoplasm of the chief cells. These findings suggest that NPY may be stored in the core of granules of the chief cells of the carotid body in young rats.