Konashi S, Takahashi K, Akiba Y
Department of Animal Science, Faculty of Agriculture, Tohoku University, Sendai-shi, Japan.
Br J Nutr. 2000 Apr;83(4):449-56.
Two experiments were conducted to determine the effects of essential amino acid deficiencies on several immunological variables in male broiler chickens. Essential amino acids were classified into five groups as follows: S-containing amino acids (SAA; methionine + cysteine), aromatic amino acids (AAA; phenylalanine + tyrosine), branched-chain amino acids (BCAA; isoleucine + leucine + valine), arginine plus lysine (Arg + Lys), and other essential amino acids (OEAA; glycine + serine + histidine + threonine + tryptophan). Chickens were fed ad libitum from 10 to 24 d of age on a control diet or amino-acid-deficient diets formulated to contain each amino acid group at 50% and 16% (Expt 1) at 50% (Expt 2) of the recommended requirements (National Research Council, 1984). Effects of feed consumption on immune responses were also considered by setting pair-feeding (Expt 1) or restricted-feeding (Expt 2) groups fed on the control diet. In Expt 1, changes in lymphoid organ weights varied with the type and degree of deficiency of amino acid groups, with BCAA deficiency markedly decreasing weights. The haemagglutinin titres against sheep erythrocytes did not change in any amino-acid-deficient chickens except that the titres were lower in chickens fed on the 50%- and 16%-BCAA diets as compared with their pair-fed counterparts. In Expt 2, the splenocyte proliferative response to concanavalin A was higher in the chickens fed on the BCAA- and Arg + Lys-deficient diets and lower in chickens fed on the SAA- and AAA-deficient diets than the control chickens, independent of feed consumption. These results suggest that the effects of specific amino acid deficiencies on immune responses cannot be generalized, and that BCAA have the greatest potential to modulate immune responses among the amino acids in chickens.
进行了两项实验，以确定必需氨基酸缺乏对雄性肉鸡若干免疫变量的影响。必需氨基酸分为以下五组：含硫氨基酸（SAA；蛋氨酸+半胱氨酸）、芳香族氨基酸（AAA；苯丙氨酸+酪氨酸）、支链氨基酸（BCAA；异亮氨酸+亮氨酸+缬氨酸）、精氨酸加赖氨酸（Arg+Lys）以及其他必需氨基酸（OEAA；甘氨酸+丝氨酸+组氨酸+苏氨酸+色氨酸）。从10日龄至24日龄，给鸡自由采食对照日粮或氨基酸缺乏日粮，这些日粮按照推荐需求量（国家研究委员会，1984年）的50%和16%（实验1）以及50%（实验2）配制，分别包含每组氨基酸。通过设置采食对照日粮的配对饲喂组（实验1）或限制饲喂组（实验2），还研究了采食量对免疫反应的影响。在实验1中，淋巴器官重量的变化因氨基酸组缺乏的类型和程度而异，BCAA缺乏显著降低了器官重量。除了采食50%-和16%-BCAA日粮的鸡与配对饲喂的对照鸡相比血凝素滴度较低外，任何氨基酸缺乏的鸡对绵羊红细胞的血凝素滴度均未发生变化。在实验2中，采食BCAA-和Arg+Lys-缺乏日粮的鸡对刀豆蛋白A的脾细胞增殖反应高于对照鸡，而采食SAA-和AAA-缺乏日粮的鸡则低于对照鸡，且与采食量无关。这些结果表明，特定氨基酸缺乏对免疫反应的影响不能一概而论，并且在鸡的氨基酸中，BCAA调节免疫反应的潜力最大。
