BRIEF COMMUNICATION: The relationship between milk synthesis and intracellular profiles of amino acids in the bovine mammary gland

摘要

There is a growing body of evidence that amino acid (AA) signalling in the mammary gland may play a key role in milk production of ruminants through modulation of translational regulation (Moshel et al. 2006; Toerien & Cant 2007). It has been postulated that the effect of nutrient signalling on elements of translational control of milk protein synthesis may contribute to the variable responses of milk protein yield observed following nutritional perturbations (Hanigan et al. 1998). Consistent with this hypothesis, we have reported that changes in the mean and variance of intracellular free AA (FAA) in the bovine mammary gland are associated with changes in milk protein synthesis in response to growth hormone (Pacheco et al. 2010). Using the same model, we have also reported that the nutrient-sensing mTOR pathway may be involved in the regulation of protein synthesis in the lactating bovine mammary gland (Hayashi et al. 2009). Knowledge of the potential for AA to act as signalling molecules to regulate milk protein synthesis may contribute to the development of nutritional regimes to improve milk production in dairy cows.