Amino acid requirements in inflammatory states

The metabolic disturbances that accompany an inflammatory challenge redirect nutrients from physiological processes important for growth and reproduction toward processes important in host defense. These processes can require increased provision of particular amino acids from the diet in order to spare body protein stores. The pathways that are activated in response to inflammation have to be determined in order to quantify their specific amino acid requirements. For example, increased synthesis of acute phase proteins would require additional supply of specific amino acids according to their amino acid composition. Some dispensable amino acids can become limiting because their de novo synthesis could be impaired and/or be insufficient to cover the increased demands for synthesis of important metabolites. Moreover, amino acids can act on gene expression and as mediators or signal molecules and modulate numerous functions. However, the optimal conditions, especially concentration in physiological liquids, allowing the best expression of these activities are not yet well defined.