1991 Fiscal Year Final Research Report Summary
Lectin binding sites in the stria vascularis of normal and endolymphatic hydrops-bearing guinea pigs.
| Project/Area Number |
01480408
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Kochi Medical School |
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Principal Investigator |
SEGUCHI Harumichi Department of Anatomy & Cell Biol., Kochi Medical School, Professor, 医学部, 教授 (90030866)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Toshihiro Department of Anatomy & Cell Biol., Kochi Medical School, Assist. Prof., 医学部, 助手 (40153621)
OKADA Teruhiko Department of Anatomy & Cell Biol., Kochi Medical School, Assoc. Prof., 医学部, 助教授 (00025628)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Stria vascularis / Lectins / Carbohydrates / Cationized ferritin / Apical vesicles / Endosomes / Na-K-ATPase / Guinea pig |
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| Research Abstract |
In order to clarify the function of the marginal cells in the guinea pig stria vascularis, the following three experiments were performed :
1. Lectins were employed to determine the localization of specific carbohydorates on thin sections of Lowicryl K4M embedded materials. SBA, HPA and RCA-II labeling (Gal-NAc and Gal) was observed in many apical vesicles, endosomes and apical tubules as well as on the microvilli and micropinocytotic invaginations of the luminal plasma membrane of the marginal cells. LFA labeling (sialic acid) was found on the plasma membrane of the basal infoldings of the marginal cells. WGA (Glu-NAc) was detected along the plasma membrane of all types of cells constituting the stria vascularis. The fact that the membranes of internalization, many of the apical vesicles, endosomes and apical tubules in the marginal cells possess the same carbohydrate moieties suggested that these structures. may be associated together.
2. The uptake of cationized ferritin (CF) by the a
… More
pical vesicles in the marginal cells of the stria vascularis was electron microscopically studied. CF particles were found in clusters, scattered on the free surface plasma membrane facing the endolymph and in the caveolae of the marginal cells. They were also detected in the apical vesicles, coated vesicles and endosomes. These findings suggested that the apical vesicles are associated with the free surface plasma membrane, and that they are related to the efficient exchange of ions between the endolymph and the marginal cells.
3. The effect of endolymphatic hydrops on the Na-K-ATPase activity in the stria vascularis was cytochemically investigated one year after experimental induction. The morphological observations revealed intercellular dropsy and shrinkage of the basal infoldings of the marginal cells, and shrinkage and disappearance of intermediate cells. In spite of such morphological alterations, no remarkable difference was found, as regards the localization of the Na-K-ATPase activity, between the striae vasculares of hydrops and control specimens. Less
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