Evaluation of physiological roles of various physiologically active substances in breast milk

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08460
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Medical pharmacy
• Research Institution: Nihon Pharmaceutical University
• Principal Investigator: MAEDA TOMOJI 日本薬科大学, 薬学部, 教授 (60303294)
• Co-Investigator(Kenkyū-buntansha): 千葉 健史 北海道科学大学, 薬学部, 講師 (80552926) ; 浦丸 直人 日本薬科大学, 薬学部, 講師 (90424069)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 母乳 / セロトニン / ノルアドレナリン / 生理活性物質 / 乳児

Outline of Final Research Achievements

We investigated the roles of Serotonin (5-hydroxytryptamine, 5-HT) and noradrenaline (NA) in breast milk on milk production and infants. 5-HT plays an important role in milk volume homeostasis in the mammary gland during lactation; 5-HT in milk may also affect infant development. The objective of this study was to investigate changes in 5-HT concentration in breast milk according to duration of lactation. As a result, the content of 5-HT in colostrum, 1 month and 3 months after delivery was almost the same amount. It was clarified that the mammary gland epithelial cells responsible for milk production synthesize NA and secrete it into breast milk. Furthermore, it was found that in mice that were stressed during lactation, NA in breast milk was increased and β-casein was decreased. These results suggest that physiologically active substances contained in breast milk may be involved in breast milk production and infant growth.

Free Research Field

分子薬理学

Academic Significance and Societal Importance of the Research Achievements

母乳中の生理活性物質の役割について検討を行った。母乳中の生理活性物質を測定し、乳児がどれぐらいの量の生理活性物質を服用しているかを明らかにした。したがって、今後、母乳中の生理活性物質の乳児に対する役割を見出すことができれば、母乳による育児の有益性や重要性について新たな意義が付加されると考えられる。さらに、ストレスにより母乳主成分の1つであるβ-カゼインが減少することを明らかにした。授乳期の母乳産生がどのような分子メカニズムで制御されているのかは解明されておらず、母乳中の生理活性物質の役割が明らかとなれば、母乳が出ないという悩みを抱えている母親に対する改善手段の開発に貢献することが期待できる。