γ-氨基丁酸的生物学功能及其在动物生产中的应用

Biological Functions of γ-Aminobutyric Acid and Its Application in Animal Production

γ-氨基丁酸(GABA)又名3-羧基丙胺、4-氨基丁酸或哌啶酸,是动植物体内广泛存在的非蛋白质氨基酸,具有良好的水溶性和热稳定性。GABA对中枢神经系统中的重要神经递质具有抑制作用,参与调控机体多种代谢活动。研究显示,GABA具有抗惊厥、抗焦虑、抗应激、抗肌肉松弛及镇静作用;能促进生长激素分泌、大脑蛋白质合成及提高机体抗氧化能力、繁殖性能、免疫功能等。GABA在肠道中可增加空肠绒毛长度,提高消化液分泌;在肝脏中可调节三大营养物质的储存,促进胰岛素的分泌和肝脏功能的正常运行。GABA可从食物中获取或通过谷氨酸脱羧酶(GAD)对谷氨酸脱羧后生成,随后在γ-氨基丁酸转氨酶和琥珀酸半醛脱氢酶的催化下发生不可逆反应生成琥珀酸,最终进入三羧酸循环。本文在国内外相关研究的基础上,介绍了GABA的结构与合成、代谢途径,并重点阐述了GABA促进食欲、调节肠道功能、增强免疫功能、提高抗氧化能力、调节胰岛代谢和肝脏功能、缓解氧化应激等方面的生物学功能及其在猪、家禽、反刍动物、水产动物养殖中的应用,旨在为GABA在动物生产中的应用提供参考。

γ-aminobutyric acid(GABA),also known as 3-carboxypropylamine,4-aminobutyric acid or piperidinic acid,is a non-protein amino acid widely present in plants and animals with good water solubility and heat stability.GABA plays an important role in inhibiting neurotransmitters in the central nervous system and regulating metabolism of animals.Multiple studies have shown that GABA has strong anticonvulsant,anti-anxiety,anti-stress,anti-muscle relaxation and sedative effects;GABA can promote growth hormone secretion and brain protein synthesis and improve antioxidant capacity,reproductive performance and immune function,and so on.GABA in the intestinal tract can promote the length of jejunum villi,and improve the secretion of gastric acid and digestive juices.In the liver,GABA can regulate the storage of three major nutrients and promote the secretion of insulin and maintain the normal liver function.GABA can be obtained from food or synthesized by decarboxylation of glutamate by glutamic acid decarboxylase(GAD),followed by an irreversible reaction catalyzed by GABA transaminase and succinate semialdehyde dehydrogenase to produce succinate,which ultimately enters the tricarboxylic acid cycle.In this paper,on the basis of relevant researches at home and abroad,the structure and synthesis of GABA,the metabolic pathway,and the biological functions of GABA including promoting appetite,regulating intestinal function,enhancing immune function,improving antioxidant capacity,regulating islet metabolism and hepatic function,and mitigating oxidative stress,as well as its application in swine,poultry,ruminant animals and aquaculture were reviewed so as to provide reference for its application in animal production.