title: Light, fluorescence and electron microscopic studies of rabbit subclavian glomera.
abstract: The subclavian glomera (aortic bodies) of young New Zealand white rabbits were studied with the light, fluorescence, and electron microscopes. Two cell types were identified: type I, granule-containing (chief) cells, and type II, agranular (sustentacular) cells. The type I cells possessed large nuclei, the normal complement of cytoplasmic organelles and numerous electron-opaque cytoplasmic granules. The type II cells were agranular with attenuated cytoplasmic processes which partially or completely ensheathed the type I cells. The glomera were well vascularized. Capillary endothelial cells contained numerous pinocytotic vesicles, but few fenestrae. Two profiles of nerve terminals were observed. One, apposing the type I cells, contained numerous electron-lucent vesicles, several dense-cored vesicles, mitochondria and possessed membrane specializations resembling those usually observed in synaptic zones. The other profile contained abundant mitochondria and a few electron-lucent and dense-cored vesicles. Structural specializations were not observed on the apposed membranes of these terminals or adjacent to type II cells. Fluorescence histochemistry revealed an intense yellow-green fluorescence in the glomera, which indicated the presence of biogenic amines, possibly primary catecholamines or an indolamine. The electron-opaque granules observed in the type I cells were believed to be the storage sites for these amines. The subclavian glomera were found to be morphologically similar to the carotid body which is a known chemoreceptor.
mesh_terms: D000818:Animals; D001016:Aortic Bodies / Q000032:analysis / Q000502:physiology / Q000648:ultrastructure*; D001679:Biogenic Amines / Q000032:analysis; D002628:Chemoreceptor Cells / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005260:Female; D008297:Male; D008928:Mitochondria / Q000648:ultrastructure; D010234:Paraganglia, Nonchromaffin / Q000648:ultrastructure*; D011817:Rabbits / Q000033:anatomy & histology*; D013348:Subclavian Artery / Q000294:innervation*
chemical_list: D001679:Biogenic Amines