功能性氨基酸——精氨酸和精氨酸生素在猪生产中的研究与应用进展

功能性氨基酸——精氨酸(Arg)具有重要的生理、代谢和营养作用,几乎机体中所有组织均利用Arg合成胞浆蛋白和核蛋白,精氨酸在促进肌肉蛋白质合成、增强机体的免疫力、细胞分裂、伤口复原和激素分泌等各种生理过程中,也都有着重要的角色。Arg为条件性必需氨基酸,在应激状态下和特殊生长阶段,为必需氨基酸,仔猪体内合成的精氨酸不能满足生理代谢需要。但是精氨酸的吸收与赖氨酸等拮抗,因此,对精氨酸及其内源性合成调控研究具有极大的应用价值和实践意义。精氨酸生素(Arginine activator additive,AAA)是N-乙酰谷氨酸(N-acetylglutamate,NAG)的类似物,作为一种新型的功能性氨基酸,可以有效调控内源性精氨酸合成,进而促进动物生长性能。本文就精氨酸和精氨酸生素特别是其对机体内源性精氨酸合成调控及其在仔猪和母猪中的研究进展与应用作一综述。

Arginine has many physical, metabolic and nutritional functions that include modulation of immune function, wound healing, hormone secretion, vascular tone, insulin sensitivity, lymphocytes proliferation and differentiation, cytokine production, and endothelial function. Arginine is a semi-essential amino acid that is required during periods of the body is subjected to metabolic stress situations, maximal growth, severe stress, and injury. Therefore, it is an important immunonutrient requiring adequate supplementation under these pathological situations. But its absorption affects intestinal absorption of tryptophan, lysine, or histidine. Metabolic activation of endogenous arginine synthesis may provide a new, effective strategy to augment arginine provision. N-acetylglutamate （NAG） is an allosteric activator of carbamoylphosphate synthase-I （CPS-I）, which synthesizes mitochondrial carbamoyl-phosphate necessary for the conversion of ornithine into citrulline. NAG＇s deficiency is a key factor to mitochondria of the liver and intestinal mucosa. The cytosol of mammalian cells, including enterocytes, contains a high deacylase activity to catabolize NAG, thus limiting the use of extracellular NAG to arginine synthesis. Arginine activator additive （AAA）, an analogue of NAG, is not a substrate for deacylase and therefore is a metabolically stable activator of CPS-I. AAA may help overcome the practical limitation of arginine delivery to the neonates. Advantages and effects of oral AAA administration in piglets and sows production were reviewed in this paper.