Intimate apposition of the glomus and smooth muscle cells (g-s connection) in the carotid labyrinth of juvenile bullfrogs.
Intimate apposition of the glomus and smooth muscle cells (g-s connection) was found in almost all glomus cells of the carotid labyrinths in juvenile bullfrogs, Rana catesbeiana. There were three types of g-s connection: between thin processes (0.1-0.2 micron in width) without dense-cored vesicles of glomus cells and smooth muscle cells; between thick processes (1.0-1.5 microns in width) with dense-cored vesicles of glomus cells and smooth muscle cells; and between the tongue-like projections of smooth muscle cells and the flat surface of the glomus cell. In some cases, a single glomus cell made g-s connections with several smooth muscle cells. Exocytosis often occurs at the g-s connection. Afferent and efferent synapses were found on the glomus cells with g-s connections. Reciprocal synapses were also observed. On the basis of these findings, the second and third types of g-s connection are presumed to participate in vascular regulation.
Kusakabe
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Department of Anatomy, Yokohama City University School of Medicine, Japan.
D000818:Animals; D002344:Carotid Body / Q000166:cytology / Q000648:ultrastructure*; D005924:Glomus Jugulare / Q000166:cytology / Q000648:ultrastructure*; D007365:Intercellular Junctions / Q000648:ultrastructure; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000648:ultrastructure*; D011892:Rana catesbeiana; D013569:Synapses / Q000648:ultrastructure*