Konishi Y, Fuwa H
J Nutr Sci Vitaminol (Tokyo). 1982 Dec;28(6):609-20. doi: 10.3177/jnsv.28.609.
To re-evaluate nutritive values of opaque-2 (o2) and brittle-2 opaque-2 (bt2o2) maize protein and to re-estimate Gopalan's hypothesis [Lancet, i, 954-957 (1960)] that pathogenesis of pellagra might be related with intake of excess leucine and with chronic consumption of maize or jowar which contains relative high leucine, rats were fed on synthetic diets composed of amino acid mixtures simulating the protein of normal and high-lysine maize, o2 and bt2o2 maize. In order to investigate the effect of intake of excess leucine, leucine was supplemented to o2 and bt2o2 diet at the level of 0.43 and 0.73%, respectively, to adjust the ratio of leucine to isoleucine to that of normal maize protein. Judging from body weight gains and carcass nitrogen of weanling rats fed on these diets, the protein quality (amino acid composition) of bt2o2 maize was 30% superior nutritionally to that of o2 maize, and body composition of bt2o2 diet group were similar to that of casein diet group. Leucine supplementation did not affect these values except for a significant decrease in plasma valine levels. In young adult rats fed on leucine supplemented o2 diet, excretion of urinary nitrogen increased significantly compared with o2 diet alone, suggesting that a slight amino acid imbalance took place. But leucine supplementation altered neither N1-methylnicotinamide level in urine nor total niacin levels in the liver and the brain. These results suggest that supplementation of leucine to a high lysine maize diet did not affect tryptophan and niacin metabolism in rats under these conditions.
为了重新评估粉质胚乳2（o2）和粉质胚乳2-脆胚乳2（bt2o2）玉米蛋白的营养价值，并重新评估戈帕兰的假说[《柳叶刀》，i，954 - 957（1960）]，即糙皮病的发病机制可能与亮氨酸摄入过量以及长期食用含有相对较高亮氨酸的玉米或高粱有关，用由模拟正常和高赖氨酸玉米、o2和bt2o2玉米蛋白的氨基酸混合物组成的合成饲料喂养大鼠。为了研究亮氨酸摄入过量的影响，分别在o2和bt2o2饲料中添加0.43%和0.73%的亮氨酸，以将亮氨酸与异亮氨酸的比例调整到正常玉米蛋白的比例。从以这些饲料喂养的断奶大鼠的体重增加和胴体氮含量来看，bt2o2玉米的蛋白质质量（氨基酸组成）在营养上比o2玉米高30%，并且bt2o2饲料组的身体组成与酪蛋白饲料组相似。除了血浆缬氨酸水平显著降低外，补充亮氨酸并未影响这些值。在以添加亮氨酸的o2饲料喂养的成年幼鼠中，与单独的o2饲料相比，尿氮排泄显著增加，这表明发生了轻微的氨基酸失衡。但是补充亮氨酸既没有改变尿中N1-甲基烟酰胺水平，也没有改变肝脏和大脑中的总烟酸水平。这些结果表明，在这些条件下，向高赖氨酸玉米饲料中补充亮氨酸不会影响大鼠体内色氨酸和烟酸的代谢。
