Exploration of the role of glucagon in the crosstalk between glucose metabolism and amino acid metabolism

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H04681
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental physiology(including physical medicine and nutritional physiology)
• Research Institution: Nagoya University
• Principal Investigator: Hayashi Yoshitaka 名古屋大学, 環境医学研究所, 教授 (80420363)
• Research Collaborator: ODA HIROAKI ; SEINO YUSUKE
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: グルカゴン / アミノ酸 / 糖新生 / 肝臓 / 糖尿病 / 膵臓ランゲルハンス島 / エネルギー代謝 / 蛋白質

Outline of Final Research Achievements

Glucagon was originally reported as a hyperglycemic substance that is present in pancreatic extract in 1923, the year of the Nobel Prize in Physiology or Medicine given to discovery of insulin. Therefore, the major physiological role of glucagon has been considered to raise blood glucose levels. However, mice deficient in glucagon gene, which we have produced, are normoglycemic and displayed increased serum amino acid levels. Our effort has been made to explore mechanisms involved in glucagon-dependent regulation of amino acid metabolism. Several lines of data and evidence are indicating that “truly” specific and physiological role of glucagon is regulation of amino acid catabolism, especially conversion of amino acids to substrates available for gluconeogenesis.

Free Research Field

内分泌代謝学

Academic Significance and Societal Importance of the Research Achievements

グルカゴンは血糖値を上げるホルモンであると広く認知され、糖尿病においては血糖値を上昇させることにより病態を悪化させる「悪役」とも考えられてきた。しかしながら、我々が独自に作成したグルカゴンを欠損する動物モデルを詳細に解析した結果、グルカゴンは蛋白質の構成要素であるアミノ酸の血中濃度の維持に必要不可欠な役割を持つことが明らかとなった。生体におけるアミノ酸代謝の制御のしくみは未解明の部分が多く、我々の成果をさらに展開することにより、糖尿病学・栄養学のみならず生命科学全般に広く影響を及ぼす新しい知見がもたらされることが期待できる。