Amino acid requirements in inflammatory states

Abstract

Obled, C. 2003. Amino acid requirements in inflammatory states. Can. J. Anim. Sci. 83: 365-373. 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.Key words: Amino acids, requirements, inflammation, protein, metabolism, glutathione, glutamine Obled, C. 2003. Besoin en acides aminés dans les situations inflammatoires. Can. J. Anim. Sci. 83: 365-373. Les perturbations métaboliques qui accompagnent les états inflammatoires sont caractérisées par une redistribution des nutriments vers les processus impliqués dans la défense de l'organisme au détriment des processus de croissance et de reproduction. L'activation de nombreuses voies métaboliques peut nécessiter un apport alimentaire accru de certains acides aminés de façon à épargner les protéines musculaires. La nature de ces voies métaboliques doit être déterminée pour mieux connaître les implications en terme de besoin en acides aminés. Par exemple, la synthèse des protéines de la réaction inflammatoire peut requérir des apports en acides aminés particuliers selon leur composition. Certains acides aminés non indispensables peuvent devenir limitants si leur synthèse endogène n'est pas suffisante pour répondre à la synthèse accrue de métabolites importants. De plus, les acides aminés peuvent moduler l'expression des gènes et agir comme de véritables médiateurs. Ils peuvent ainsi réguler plusieurs fonctions métaboliques. Cependant, les conditions, en particulier de concentration dans les liquides physiologiques, permettant d'optimiser ces activités restent le plus souvent à déterminer.

Effect of banding or burdizzo castration on plasma testosterone, acute-phase proteins, scrotal circumference, growth, and health of bulls

“…However, during d 15 to 28 after castration the ADG of BURD castrates seemed to be recovered compared with CON. The reduction in growth may be, in part, due to the immediate tissue trauma, inflammation (Obled, 2002), and probably psychological (pain) stress in response to castration, and the loss of anabolic (testosterone) steroid ( Knight et al, 1999a and b). BURD had an advantage in ADG over BAND in the period of d 15-28 post-castration.…”

Intestinal, hepatic, splanchnic and hindquarter amino acid and metabolite partitioning during an establishedTrichostrongylus colubriformisinfection in the small intestine of lambs fed fresh Sulla (Hedysarum coronarium)

“…Intestinal glutamine requirement has also been linked to the activation of the immune response during infection 33 . Thus, the increased uptake of glutamine by the MDV (P¼0 •14) and PDV (P, 0•05) of parasitised lambs may be due to increased requirements by the intestine for the repair of damaged tissue and local immune response.…”

“…Threonine was released from the liver of parasitised lambs compared with a net uptake for the control lambs. Threonine is an important EAA for acute-phase protein synthesis in the liver during immune responses 33 and for intestinal secretions 34 -36 . The reason for increased hepatic utilisation of only the BCAA in the parasitised lambs is unclear.…”

Physiological responses of growing pigs to high ambient temperature and/or inflammatory challenges

“…In addition, sick animals are often in anorexic state and have to rely on mobilization of body reserves to meet their nutritional needs. Skeletal muscle catabolism increases free amino acids into the circulation that, in turn, can be used in the liver for the synthesis of acute phase proteins, as well as substrate for gluconeogenesis (Hasselgren and Fischer, 1999;Leverve, 2001;Obled, 2003). Accordingly, Daiwen et al (2008) observed lower protein retention in pigs challenged intramuscularly with LPS when compared with their pair-fed counterparts receiving a saline solution.…”