1992 Fiscal Year Final Research Report Summary
Calcium frux and localization of Ca^<++>-ATPases in oral mucosal mechanoreceptors
| Project/Area Number |
03670850
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Morphological basic dentistry
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| Research Institution | Iwate Medical University |
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Principal Investigator |
TACHIBANA Tamiko Iwate Medical University, Sch.Dentistry, Assistant Professor, 歯学部, 助教授 (10089386)
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| Co-Investigator(Kenkyū-buntansha) |
TACHIBANA Tamiko Iwate Medical University, Sch.Dentistry, Assistant Professor (10089386)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Mechanoreceptor / Meissner corpuscle / Merkel corpuscle / Ca^<++> / Ca^<++>-pump / Ca^<++> / Mg^<++>-ATPase / Trifluoperazine / Amiloride |
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| Research Abstract |
Oral mucosal mechanoreceptors are physiologically classified into two categories : rapidly adapting and slowly adapting receptors. The reasons for the functional difference between these receptors have not been fully elucidated yet. In this study, the calcium flux and the kinds and localization of Ca^<++>-ATPases in Meissner corpuscles (rapidly adapting receptor) and Merkel corpuscle (slowly adapting receptor) in the palatine mucosa of the Mongolian gerbil were cytochemically compared. It was found that mechanical stimulations to palatine rugae induce influxes of Ca^<++> into axon terminals of these receptors. The author presumed the presence of Ca^<++>-ATPases as systems for the extrusion of the Ca^<++> from axons, so cytochemical explorations were made. As the result, Meissner corpuscles exhibited a strong activity of Ca^<++>-pump ATPase on the axoplasmic membrane and a strong activity of Ca^<++>/Mg^<++>-ATPases on the lamellar cell membrane. However, the Ca^<++>-pump ATPase was not localized on the axoplasmic membrane of Merkel corpuscles, though a weak activity of Ca^<++>/Mg^<++>-ATPase was detected. Trifluoperazine, an inhibitor for Ca^<++>-pump, was found to inhibit the Ca^<++> extrusion from axon terminals of mechanically stimulated Meissner corpuscles but not of Merkel corpuscles. While, the Ca^<++>-extrusion from nerve terminals of Merkel cell-axon complexes was severely influenced with amiloride, which is known as an inhibitor of the Na^+/Ca^<++> exchanger. Thus, it is conceived that Ca^<++>-extrusion in the axon terminals of Meissner corpuscles and Merkel corpuscles are regulated by different systems from each other.
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