REGULATION OF ALBUMIN SYNTHESIS BY HORMONES AND AMINO-ACIDS IN PRIMARY CULTURES OF RAT HEPATOCYTES
REGULATION OF ALBUMIN SYNTHESIS BY HORMONES AND AMINO-ACIDS IN PRIMARY CULTURES OF RAT HEPATOCYTES
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DOI：
10.1152/ajpendo.1987.252.3.e291
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发表时间：
1987-03-01
影响因子：
--
通讯作者：
JEFFERSON, LS
中科院分区：
文献类型：
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作者：
HUTSON, SM;STINSONFISHER, C;JEFFERSON, LS
在化学定义的无血清培养基中，研究了优化白蛋白分泌所需的培养条件。培养基的氨基酸分析是基于Ham' s F12:Dulbecco' s modified Eagle培养基（未添加培养基）的1:1混合物，发现在24小时的培养过程中，该培养基中某些必需氨基酸被消耗掉了。当培养基中添加额外的氨基酸（补充培养基）时，白蛋白分泌率显着提高并保持得更好。此外，选择性去除必需氨基酸导致总蛋白和白蛋白合成立即减少，并在48小时后进一步选择性减少白蛋白合成。在各种实验条件下观察到白蛋白分泌的线性率，但分泌并不严格与细胞数量成正比。在2-3倍的电镀密度下获得最大的分泌率。106个细胞/ 60mm培养皿。白蛋白分泌也随着培养时间的增加而增加，在第3天和第4天达到最大值。当单独添加时，输注或地塞米松均以剂量依赖的方式增加白蛋白分泌率，但激素和充足的氨基酸供应对于最大分泌率以及肝细胞的长期维持（bbb3 -4天）是必要的。在地塞米松存在的情况下，胰岛素的剂量-反应曲线向生理胰岛素浓度偏移。在添加激素的培养基中，白蛋白分泌率的变化与白蛋白合成和白蛋白mRNA的相对量的变化是平行的。基因转录的变化可能与此有关。
Culture conditions necessary for optimizing albumin secretion were studied in rat hepatocytes maintained in a chemically defined, serum-free medium. Amino acid analysis of the culture medium, which was based on a 1:1 mixture of Ham''s F12:Dulbecco''s modified Eagle''s medium (unsupplemented medium), revealed that certain essential amino acids were depleted from this medium over a 24-h incubation. Rates of albumin secretion were significantly higher and better maitained when the medium was supplemented with additional amino acids (supplemented medium). Moreover, selective removal of an essential amino acids resulted in an immediate decrease in total protein and albumin synthesis and after 48 h a further selective decrease in albumin synthesis. Linear rates of albumin secretion were observed over a wide variety of experimental conditions, but secretion was not strictly proportional to cell number. Maximal rates of secretion were obtained at plating densities of 2-3 .times. 106 cells/60 mm culture dish. Albumin secretion also increased with time in culture reaching a maximum on days 3 and 4. When added singly, either infusion or dexamethasone increased rates of albumin secretion in a dose-dependent manner, but both hormones and an adequate supply of amino acids were necessary for maximal rates of secretion as well as long-term maintenance of the hepatocytes (> 3-4 days). In the presence of dexamethasone the dose-response curve for insulin was shifted toward physiologic insulin concentrations. Changes in rate of albumin secretion in response to added hormones in supplemented media were found to parallel changes in albumin synthesis and relative amounts of albumin mRNA. Changes in gene transcription were probably involved.