复合氨基酸对断奶仔猪肝脏能量状态、游离氨基酸含量及其相关基因表达的影响

为进一步探明复合功能性氨基酸的应用效果与机理，在前期研究的基础上，本试验研究了日粮中添加复合氨基酸对断奶仔猪肝脏能量状态、游离氨基酸及相关基因表达的影响。将16头体重相近的（21±3）日龄断奶仔猪随机分为对照组和复合氨基酸组，每组8个重复。分别饲喂添加0.99%丙氨酸（与试验组等氮）和1.00%复合氨基酸（谷氨酸：谷氨酰胺：精氨酸：甘氨酸：N-乙酰半胱氨酸=5：2：2：1：0.5）的基础日粮。于试验第21天前腔静脉采血，屠宰取肝脏样品，待测。结果表明，与对照组相比，复合氨基酸显著降低了仔猪血浆ALT和AST活性（P<0.05）；显著提高了仔猪肝脏总蛋白含量、RNA/DNA和总蛋白/DNA（P<0.05），显著降低了仔猪肝脏MDA和H₂O₂含量（P<0.05）；显著提高了肝脏精氨酸和二磷酸腺苷（ADP）含量（P<0.05）；显著上调了肝脏氨基酸转运载体b^0，+AT和y⁺LAT2基因、谷胱甘肽硫转移酶ω2基因（GSTO2）、干扰素γ基因（IFN-γ）、脂蛋白酯酶基因（LPL）的表达（P<0.05），显著下调了脂肪酸合成酶基因（FASN）的表达（P<0.05）。以上结果表明，日粮中添加1.00%复合氨基酸可以改善肝功能，提高抗氧化能力，可以调控仔猪肝脏能量状态及游离氨基酸代谢，并可能影响肝脏的脂肪代谢和免疫功能。

Effects of Amino Acid Blend on Liver Energy State,Free Amino Acids and Relative Expression of Related Genes in Weaned Piglets

In order to further explore the application effects and mechanism of an amino acid blend (AAB),this study investigated the effects of dietary supplementation with AAB on liver energy state,free amino acids and relative expression of related genes in weaned piglets following our previous studies.Sixteen (21±3) days old weaned piglets with similar body weight were randomly assigned to control group and AAB group,with 8 replicates per group.The diet of the control group was basal diet supplemented with 0.99% alanine (isonitrogenous control),the diet of AAB group was basal diet supplemented with 1.00% AAB (glutamate:glutamine:glycine:arginine:N-acetylcysteine=5:2:2:1:0.5).On day 21 of the trial,the blood and liver samples were obtained from all piglets.The results indicated that:Compared to the control group,AAB group decreased plasma ALT and AST activity in piglets (P<0.05),increased the total protein content,RNA/DNA and total protein/DNA in the liver of piglets(P<0.05),reduced the MDA and H₂O₂ contents in the liver of piglets (P<0.05),increased the liver arginine and adenosine diphosphate (ADP) levels (P<0.05),increased mRNA levels of amino acid transporter b^0,+ AT and y⁺ LAT2 genes,glutathione S-transferase ω2 gene (GSTO2),interferon-γ gene (IFN-γ),lipoprotein lipase gene (LPL) (P<0.05),decreased mRNA levels of fatty acid synthase gene (FASN) (P<0.05).The above results showed that the addition of 1.00% AAB could improve the liver function,improve the antioxidant capacity,regulate the energy state and free amino acid metabolism of piglet liver,and might affect the fat metabolism and immune function of liver.