Expressions of fatty acid receptors, the 6th taste sensation, in various organs

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K07995
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Animal production science
• Research Institution: Kitasato University
• Principal Investigator: Taniguchi Kazumi 北里大学, 獣医学部, 准教授 (00171843)
• Co-Investigator(Kenkyū-buntansha): 眞鍋 昇 大阪国際大学, その他部局等, 教授 (80243070)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 味覚受容体 / 脂肪 / 遊離脂肪酸受容体 / Ffar / 発生 / 味蕾 / 腸 / 膵臓

Outline of Final Research Achievements

Expressions of fatty acid receptors 1, 2, 3 and 4 were observed along the time course of the ontogenetic development using Wistar rats. Taste buds of circumvallate papillae, foliate papillae, and fungiform papillae were obtained along the time course of the ontogenetic development, including fetal, neonatal, postnatal and adult stages. In addition, ileum, colon, and pancreas were observed in these stages. The amounts of messenger RNAs were measured by real-time PCR using Taqman probes. The localizations of these fatty acid receptors were observed by immunohistochemistry.
These observations revealed the expressions of mRNAs of the fatty acid receptors in the taste buds and the GI tract through fetal to adult stages. Also, their immunohistochemical localizations were observed in the taste cells of all papillae examined. These results suggest the possibility that fatty acid receptors 1 to 4 perceives fat taste, as the 6th taste sensation.

Free Research Field

獣医解剖学・獣医組織学・獣医発生学

Academic Significance and Societal Importance of the Research Achievements

味覚の要素として、これまで甘味、苦味、酸味、塩味、それに旨味が５つの要素として広く認識されてきた。本研究は脂肪の味に注目し、これを受容する4種類の遊離脂肪酸受容体に注目して、その詳細を免疫組織化学および定量的PCRにより明らかにしたものであり、また胎生期から成体に至るまでの発生を詳細に明らかにしたものである。結果、4種類の脂肪酸受容体は胎生期から成体に至るまで発現しており、舌の味蕾のみならず、回腸、結腸、膵臓でも胎生期から成体に至るまで発現していることを明らかにした。
この結果は、脂肪味が第６の味覚要素として極めて有力であることを示すものである。