1995 Fiscal Year Final Research Report Summary
Molecular mechanisms of transduction of gustatory stimuli in human and mammalian tatse cells.
| Project/Area Number |
05404063
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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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 |
SATO Toshihide Nagasaki University, School of Dentistry, Professor, 歯学部, 教授 (60013968)
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| Co-Investigator(Kenkyū-buntansha) |
MATAKI Shiro Tokyo Medical and Dental University, Faculty of Dentistry, Associate Professor, 歯学部, 助教授 (80157221)
FUJIYAMA Rie Nagasaki University, School of Dentistry, Research Associate, 歯学部, 助手 (10274664)
MIYAMOTO Takenori Nagasaki University, School of Dentistry, Research Associate, 歯学部, 助手 (10167679)
OKADA Yukio Nagasaki University, School of Dentistry, Associate Professor, 歯学部, 助教授 (60136687)
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| Project Period (FY) |
1993 – 1995
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| Keywords | Taste Cell / Taste Receptive Membrane / Ion Channel / cAMP / IP_3 / Basolateral Membrane / Four Basic Stimuli / Ca |
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| Research Abstract |
There are cation and anion channels on the receptive membrane of frog taste cells. Na^+ and Cl^- of NaCl stimuli pass through the cation channel and the anion channel, respectively. Since the Cl^- permeability is lower, a depolarization appears in the taste cell.
We found 80 pS and 40 pS K^+ channels in the frog taste cell membranes. 80 pS K^+ channel in dependent on voltage and Ca^<2+>, but 40 pS K^+ channel is not. Closure of 40 pS K^+ channels is related to cAMP and protein kinase A.Both types of the K^+ channels exist densily on the receptive and dendritic membranes.
Application of amiloride to the receptive membrane of a mouse taste cell within the taste bud produced an outward current, but application of it to the basolateral membrane did not. This suggests that amoloride-sensitive Na^+ channels exist mostly in the receptive membrane.
There are two transduction pathways for sweet stimuli in gerbil taste cells. The gustatory transduction for sugars is concerned with a second messenger cAMP,but that for non-sugars like amino acids is concerned with IP_3.
We have measured internal Ca^<2+> concentration in human taste buds of the fungiform papillae during taste stimulation. Different taste stimuli caused a change in Ca^<2+> concentration of different taste cells in the taste bud, indicating that each taste cell has differential chemical sensitivity.
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