title: Three-dimensional and ultrastructural relationships between intermediate cells and capillaries in the gerbil stria vascularis.
abstract: Structural relationships between intermediate cells and capillaries in the stria vascularis of gerbils were examined by confocal laser microscopy and electron microscopy. Immunostaining for an inward rectifier K(+) channel (Kir4.1), which was localized to intermediate cells, was used to determine the three-dimensional distribution of intermediate cells. These cells constituted a honeycomb-like network, and their dendritic processes surrounded not only capillaries but also the basolateral surface of epithelial marginal cells. On the basis of the above finding and the large K(+) conductance in intermediate cells, we propose that the network composed of intermediate cells has a spatial K(+) buffering function. Transmission electron microscopy revealed the absence of the basal lamina in some regions and the presence of a gap junction-like membrane association between intermediate cells and pericytes and/or endothelial cells. This result supported our previous finding that intermediate cells were dye-coupled with pericytes and endothelial cells. The presence of gap junctions between intermediate cells and pericytes and/or endothelial cells suggests that endothelial cells and pericytes may play roles other than forming a structural route for blood circulation.
authors.affiliation: Department of Physiology, Kochi Medical School, Nankoku 783-8505, Japan. takeuchi@kochi-ms.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Takeuchi
authors.forename: M
authors.initials: M
authors.lastname: Ando
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: A
authors.initials: A
authors.lastname: Kakigi
mesh_terms: D000818:Animals; D002196:Capillaries / Q000648:ultrastructure; D002450:Cell Communication; D017629:Gap Junctions / Q000378:metabolism / Q000648:ultrastructure; D005849:Gerbillinae; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D024661:Potassium Channels, Inwardly Rectifying; D013316:Stria Vascularis / Q000166:cytology* / Q000378:metabolism
chemical_list: D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D011188:Potassium