1995 Fiscal Year Final Research Report Summary
STUDIES ON THE GUSTATORY SIGNAL TRANSDUCTION MECHANISMS OF MOUSE TASTE CELLS USING CONGENIC CELL LINE
| Project/Area Number |
06671862
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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 |
Functional basic dentistry
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| Research Institution | Nagasaki University |
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Principal Investigator |
MIYAMOTO Takenori Nagasaki University, School of Dentistry, Research Associate, 歯学部, 助手 (10167679)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Mouse Taste Cell / Patch Clamp / Non-Dissociated Cell / Strain Difference / Salt Response / Amiloride / Sweet Response / D-Phenylalanine |
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| Research Abstract |
The taste responses to salt-stimuli are known to represent a strain-differences. For example, the salt response of C57BL/6 strain indicates strong amiloride sensitivity, but that of BALB/c does not. we attempted to examine differences of the taste responses among taste cells obtained from these two strains and a congenic strain derived from BALB/c strain. We developed a method to obtain taste responses from non-dessociated taste cells, which are embedded in the taste bud so as to maintain those polarity, using patch clamp technique. This method enable us to perform the localized stimulation to the apical membrane alone. The results is as follows :
(1) Both amiloride-sensitive and -insensitive components are involved in the salt responses of the mouse taste cells. The suppression of K^+ channels was suggested to be one of amiloride-insensitive components.
(2) The salt responses were categorized into three types :
(a) Type I consisted of both amiloride-sensitive and -insensitive components ;
(b) Type II involved amiloride-sensitive component alone ;
(c) Type III involved amiloride-insensitive component alone. Since the higher aversion threshold to NaCl was known to be observed in BALB/c mouse than in C57BL/6, the amiloride-insensitive pathway may relate to the transduction pathway for a different quality of taste from that the amiloride-sensitive pathway does. An involvement of the suppression of K^+ channels, which is one of the sweet taste transduction mechanisms, in the amiloride-insensitive pathway supports this hypothesis. For sweet taste, we have found few number of taste cells responded to D-phenylalanine (D-Phe) so far. In such taste cells responded to D-Phe, both 5'-GMP and saccharin enhanced the response to D-Phe.
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