Amino acid transportation, sensing and signal transduction in the mammary gland: key molecular signalling pathways in the regulation of milk synthesis

Nutr Res Rev. 2020 Dec;33(2):287-297. doi: 10.1017/S0954422420000074. Epub 2020 Mar 10.


The mammary gland, a unique exocrine organ, is responsible for milk synthesis in mammals. Neonatal growth and health are predominantly determined by quality and quantity of milk production. Amino acids are crucial maternal nutrients that are the building blocks for milk protein and are potential energy sources for neonates. Recent advances made regarding the mammary gland further demonstrate that some functional amino acids also regulate milk protein and fat synthesis through distinct intracellular and extracellular pathways. In the present study, we discuss recent advances in the role of amino acids (especially branched-chain amino acids, methionine, arginine and lysine) in the regulation of milk synthesis. The present review also addresses the crucial questions of how amino acids are transported, sensed and transduced in the mammary gland.

Keywords: Amino acids; Mammary gland; Milk fat; Milk protein; Signalling pathways.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acids / chemistry*
  • Animals
  • Fats / chemistry*
  • Female
  • Humans
  • Lipid Metabolism
  • Mammary Glands, Animal / physiology*
  • Mammary Glands, Human / physiology*
  • Milk / chemistry
  • Milk Proteins / chemistry*
  • Protein Biosynthesis
  • Signal Transduction


  • Amino Acids
  • Fats
  • Milk Proteins