Maurice M, Lardeux B, De Saint-Steban C, Bourdel G, Feldmann G
J Nutr. 1986 Nov;116(11):2132-41. doi: 10.1093/jn/116.11.2132.
The influence of protein ingestion on liver albumin synthesis and albumin content was investigated in rats fed protein as a meal (90% casein) given apart from the other dietary components provided ad libitum. In this condition, protein ingestion rapidly stimulates liver total protein synthesis. Separately fed rats were studied 6 and 20 h after the protein meal. Control rats fed mixed diets containing 13 or 80% casein were killed either during the absorptive (night) or postabsorptive (light) periods. The ratio of hepatic albumin synthesis to total protein synthesis remained fairly constant (12-15%) in all groups, indicating that albumin synthesis paralleled total protein synthesis. Liver albumin content measured in microsomes by immunonephelometry was significantly higher in separately fed rats killed 6 h postmeal than in those killed after 20 h. In rats fed 13% casein, the liver albumin content remained high regardless of the time of killing. In rats fed 80% casein, the albumin content was higher during the absorptive period than during the postabsorptive period. Immunoperoxidase staining of the hepatocyte organelles involved in albumin synthesis, especially the Golgi apparatus, was more intense for separately fed rats killed 6 h postmeal than for those killed after 20 h. Livers of rats fed 13% casein also exhibited a pattern indicative of high hepatocyte albumin content, whereas livers of rats fed 80% casein contained less. These results show that, in separate feeding, wide circadian variations of albumin synthesis run parallel to changes in liver albumin content.
在将蛋白质作为一顿饭（90%酪蛋白）喂食大鼠的实验中，研究了蛋白质摄入对肝脏白蛋白合成及白蛋白含量的影响，该餐食与随意提供的其他饮食成分分开给予。在这种情况下，蛋白质摄入迅速刺激肝脏总蛋白质合成。对单独喂食的大鼠在进食蛋白质餐后6小时和20小时进行研究。喂食含13%或80%酪蛋白混合饮食的对照大鼠在吸收期（夜间）或吸收后期（白天）被处死。所有组中肝脏白蛋白合成与总蛋白质合成的比率保持相当恒定（12 - 15%），这表明白蛋白合成与总蛋白质合成平行。通过免疫比浊法在微粒体中测量的肝脏白蛋白含量，在餐后6小时处死的单独喂食大鼠中显著高于餐后20小时处死的大鼠。在喂食13%酪蛋白的大鼠中，无论处死时间如何，肝脏白蛋白含量都保持较高水平。在喂食80%酪蛋白的大鼠中，吸收期的白蛋白含量高于吸收后期。参与白蛋白合成的肝细胞细胞器，特别是高尔基体，餐后6小时处死的单独喂食大鼠的免疫过氧化物酶染色比餐后20小时处死的大鼠更强。喂食13%酪蛋白的大鼠肝脏也呈现出肝细胞白蛋白含量高的模式，而喂食80%酪蛋白的大鼠肝脏含量较少。这些结果表明，在单独喂食时，白蛋白合成的昼夜变化幅度较大，与肝脏白蛋白含量的变化平行。
