Attaix D, Manghebati A, Grizard J, Arnal M
Biochim Biophys Acta. 1986 Jul 16;882(3):389-97. doi: 10.1016/0304-4165(86)90263-1.
Week-old lambs received an intravenous injection of 4.3, 8.5, 12.8 or 17.1 mmol [3H]valine/5 kg body weight, i.e., 3.6-14.4-times the whole-body free valine content. To ensure that protein synthesis measurements in lambs are reliable within a 30-min period, these large amounts of valine must account for at least around 11-times the total free pool of valine. This amounted to 12.8 mmol valine/5 kg body weight. There were no significant variations in plasma insulin and plasma glucagon levels 5, 13 and 30 min after the injection of so much valine. The fractional rates of protein synthesis were determined in tissues of animals receiving either 12.8 or 17.1 mmol valine/5 kg body weight. The rates of protein synthesis in the jejunum (87.5%/day), liver (106.6%/day) and tensor fasciae latae muscle (18.8%/day) of lambs injected with the 12.8 mmol [3H]valine flooding dose, were in the range of data obtained in immature rats. Increasing the flooding amount of valine up to 17.1 mmol/5 kg body weight did not significantly alter protein synthesis rates in the jejunum, liver or skeletal muscle. This suggested that both the flooding-dose method in itself and valine had no effect on in vivo protein synthesis.
一周大的羔羊静脉注射4.3、8.5、12.8或17.1 mmol [³H]缬氨酸/5 kg体重，即全身游离缬氨酸含量的3.6 - 14.4倍。为确保在30分钟内羔羊蛋白质合成测量结果可靠，这些大量的缬氨酸必须至少占缬氨酸总游离池的11倍左右。这相当于12.8 mmol缬氨酸/5 kg体重。注射如此大量缬氨酸后5、13和30分钟，血浆胰岛素和血浆胰高血糖素水平无显著变化。在接受12.8或17.1 mmol缬氨酸/5 kg体重的动物组织中测定蛋白质合成的分数率。注射12.8 mmol [³H]缬氨酸冲击剂量的羔羊空肠（87.5%/天）、肝脏（106.6%/天）和阔筋膜张肌（18.8%/天）的蛋白质合成率在未成熟大鼠获得的数据范围内。将缬氨酸的冲击量增加至17.1 mmol/5 kg体重并未显著改变空肠、肝脏或骨骼肌中的蛋白质合成率。这表明冲击剂量法本身和缬氨酸对体内蛋白质合成均无影响。
