The glomus cells and an extensive network of nerve fibers between them in the rat carotid body fluoresce intensely after exposure to hot paraformaldehyde vapor. Virtually all the glomera fluoresce. Sympathectomy results in disappearance of the fluorescent nerve fibers between the glomus cells; hence, these nerve fibers are noradrenergic. Reserpine administration depletes the fluorescence of glomus cells and nerve fibers. Administration of l-dopa after reserpine restores the fluorescence to the glomus cells, but not to the noradrenergic nerve fibers. Administration of l-dopa after reserpine in other tissues restores fluorescence to dopaminergic but not to noradrenergic nervous elements. The intense noradrenergic innervation of atrial heart muscle and blood vessels does not refluoresce after the sequential administration of reserpine and l-dopa, nor do sympathetic ganglion cells. After reserpine and l-dopa administration, all glomera fluoresce, although it is possible that a few isolated glomus cells within the glomera are not rendered refluorescent. It appears most likely that virtually all glomus cells contain dopamine but not noradrenaline. It is suggested that virtually all the noradrenaline present biochemically in the carotid body is located in the autonomic nerve fibers ramifying in the carotid body and in the sporadic ganglion cells found in and adjacent to the carotid body, but not in the glomus cells. © 1978.
Hess, A. (1978). Are glomus cells in the rat carotid body dopaminergic or noradrenergic? Neuroscience, 3(4–5), 413–418. https://doi.org/10.1016/0306-4522(78)90043-X