Lambert A J, Merry B J
School of Biological Sciences, Derby Building, University of Liverpool, L69 3BX, Liverpool, UK.
Exp Gerontol. 2000 Aug;35(5):583-94. doi: 10.1016/s0531-5565(00)00101-7.
Primary cultures of hepatocytes are widely used to investigate liver function, but this technology has not been exploited fully in the study of ageing and caloric restriction (CR). Hepatocytes were isolated from adult and aged, fully fed, and calorie restricted male Sprague-Dawley rats and their viability and biochemical status assessed over 48h in primary culture. The in vivo differences in cellular protein and DNA content due to age and CR were maintained over the 48h experimental period. The results of this study confirm earlier reports that protein synthesis and degradation rates decline with age in liver tissue, and this decline is retarded by CR. Rates of protein synthesis and degradation in the first year of life were depressed in response to CR feeding and were only significantly higher than recorded for control animals during the second year of life. Cells from rats of both ages and diets maintained linear rates of extracellular protein synthesis, intracellular protein synthesis, protein degradation and albumin secretion between 24 and 48h in culture. These findings indicate that hepatocytes from CR rats did not respond adversely to the relatively rich culture medium and cells from CR animals did not immediately revert to the fully fed phenotype.
肝细胞原代培养被广泛用于研究肝功能，但这项技术在衰老和热量限制（CR）研究中尚未得到充分利用。从成年和老年、饱食及热量限制的雄性斯普拉格-道利大鼠中分离肝细胞，并在原代培养中对其活力和生化状态进行48小时的评估。在48小时的实验期内，因年龄和热量限制导致的细胞蛋白质和DNA含量的体内差异得以维持。本研究结果证实了早期报告，即肝组织中蛋白质合成和降解速率随年龄下降，而热量限制可减缓这种下降。生命第一年的蛋白质合成和降解速率因热量限制喂养而降低，仅在生命第二年显著高于对照动物记录值。来自不同年龄和饮食的大鼠的细胞在培养24至48小时之间维持细胞外蛋白质合成、细胞内蛋白质合成、蛋白质降解和白蛋白分泌的线性速率。这些发现表明，热量限制大鼠的肝细胞对相对丰富的培养基没有不良反应，且热量限制动物的细胞不会立即恢复到饱食表型。
