1990 Fiscal Year Final Research Report Summary
Identification and Transduction Mechanisms in Chemoreceptor Cells
| Project/Area Number |
63480496
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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 |
代謝生物化学
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| Research Institution | Hokkaido University |
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Principal Investigator |
KURIHARA Kenzo Hokkaido Univ. Pharmaceutical Sciences, Professor, 薬学部, 教授 (00016114)
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| Co-Investigator(Kenkyū-buntansha) |
KASHIWAYAMAGI Makoto Hokkaido Univ. Pharmaceutical Sciences, Research Associate, 薬学部, 教務職員 (20169436)
YOSHII Kiyonori Hokkaido Univ. Pharmaceutical Sciences, Assistant Prof., 薬学部, 助手 (30125364)
MIYAKE Michihisa Hokkaido Univ. Pharmaceutical Sciences, Associate Prof., 薬学部, 助教授 (30133771)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Taste / Olfaction / Receptor / Transduction / Amiloride / Cross-adaption / Smell / Cation Channel |
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| Research Abstract |
1. Taste receptor mechanisms for salts, sweet substances and umami substances were investigated using the canine taste system. It was found that amiloride suppresses the responses to salts including NaCl, KCI and NH_4Cl. This suppression of the salt response was explained by adsorption of amiloride cation on the salt receptor sites. The responses to sugars were greatly enhanced by the presence of salts. The enhancement was explained by an increase in cooperativity between sugar receptors. It was found that canine taste system responds sensitively to umami substances. The response to monosodium glutamate (MSG) was suppressed by amiloride, but the response to disodium guanylate (GMP) or that induced by synergism between MSG and GMP was not suppressed by amiloride. These results suggested that the response to MSG is composed of salt response and the response to GMP alone or that induced by synergism is composed of umami response.
2. Olfactory receptor mechanisms were investigated using the turtle olfactory system. The cross adaptation method was applied to the turtle olfactory system and discrimination of various odorants was quantitatively measured. This method opened the way to study the structure-activity relationship in olfactory system. Perfusion of the turtle olfactory system with salt free solution unchanged the olfactory responsed to various odorants, suggesting that cation channels located at olfactory cilia do not contribute to in vivo olfactory system. It was found that liposomes composed of phosphatidylcholine (PC) and phosphatidylserine (PS) respond sensitively to various odorants. The sensitivity of the liposomes (PS/PC = 0.2) to amyl acetate was much higher than that of the turtle or the frog olfactory system.
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