The spatial relationship between type I glomus cells and arteriolar myocytes in the mouse carotid body.
The structural relationship between type I glomus cells and the vascular smooth muscle was investigated by electron microscopy in the mouse carotid body. A close apposition (<0.1 microm) between the glomus parenchyma and the neighbouring arterioles was regularly present. Profiles of type I glomus cells were found to be exposed to the vascular smooth muscle without any supporting cell investment. In circumscribed areas of these profiles, type I glomus cells and the vascular smooth muscle cells made contact by fusion of their basal laminae. These glomus-cell-myocyte junctions structurally resemble vascular neuromuscular junctions of sympathetic nerve terminals. In addition to the occurrence of such glomus cell-myocyte contacts, myoendothelial junctions also appeared frequently. On the basis of these observations, it is suggested that type I glomus cells play a role in the regulation of the vascular tone in the carotid body and that a physiological interaction between the endothelial cells, the vascular smooth muscle cells and the type I glomus cells exists.
El-Fadaly
Amina B
AB
Institute for Anatomy and Cell Biology, Justus-Liebig University, Aulweg 123, 35385 Giessen, Germany.
Kummer
Wolfgang
W
D000818:Animals; D001160:Arterioles / Q000166:cytology* / Q000648:ultrastructure; D002344:Carotid Body / Q000098:blood supply* / Q000166:cytology*; D051379:Mice; D032342:Muscle Cells / Q000166:cytology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000648:ultrastructure