The effects of hormone and aging on taste disorders

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K09878
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57010:Oral biological science-related
• Research Institution: Osaka University
• Principal Investigator: Wakisaka Satoshi 大阪大学, 大学院歯学研究科, 名誉教授 (40158598)
• Co-Investigator(Kenkyū-buntansha): 乾 千珠子 (山本千珠子) 大阪大学, 大学院歯学研究科, 助教 (00419459)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 味覚障害 / 亜鉛欠乏 / 加齢 / 性差 / 脳機能 / 茸状乳頭 / 女性ホルモン

Outline of Final Research Achievements

Taste disorders is known to be more common in older women, but it remains unclear. Here, we examined the relationships between sex and aging, and zinc deficiency using an animal model of zinc-deficient induced taste disorders. Zinc deficiency increased the thresholds of bitter and salty tastes in younger male and female rats, and increased the thresholds of salty taste in the middle- and older-aged female rats, but not in male rats. We examined the mechanisms of the common and differential effects of zinc deficiency in male and female rats are as follows: 1) zinc deficiency has different effects on taste receptors in male and female rats, 2) zinc deficiency reduced neural activities in the parabrachial nucleus, which is related taste information, and the supraoptic nucleus and the hypothalamic paraventricular nucleus, which are involved in body fluid regulation, in both sexes, 3) female hormone replacement in zinc-deficient female rats showed restoration of the salt taste threshold.

Free Research Field

口腔解剖学

Academic Significance and Societal Importance of the Research Achievements

味覚障害が女性が多く、特に高齢期に多く認められるという原因について、3週齢（離乳後）から80週齢（中高齢期）の雌雄の亜鉛欠乏性味覚障害モデル動物を用いた行動学的研究によって、亜鉛欠乏による影響が雄性より雌性で、特に中高齢期で強く現れることを明らかにした点で、味覚障害における亜鉛との関係に性差が生じることを示した重要な結果を示したものと考えられる。さらに女性ホルモンを補充することによって味覚が回復することを示したことは、亜鉛欠乏による女性の味覚障害に対する女性ホルモン投与療法の有効性を示す基盤的研究となりうる可能性がある。