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Biochemical Studies on Liver Functions in Primary Cultured Hepatocytes of Old Rats

老年大鼠原代培养肝细胞肝功能的生化研究

基本信息

批准号：
02670305
负责人：
MURA Tetsuo
金额：
$ 0.38万
依托单位：
Tottori University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02670305/
关键词：
Primary cultured of old rat hepatocytes Low cell density culture Fatty acid synthesis by glucagon Bile acid conjugation Peroxisome and bile acid synthesis Desmosterol conversion Hydroxylation of bile acid by dexamethasone EGF receptor assay

项目摘要

Many metabolic functions besides proliferation are regulated by cell density and that there is a reciprocal relation between cell growth and expression of hepatocyte-specific functions. On the other hand, old rat hepatocytes in primary culture are well known not to respond normally to EGF. Therefore, we examined whether any reciprocal related between cell growth and expression of hepatocyte-specific functions could be demonstrated in old rat hepatocytes by change in cell density or addition of plasma membranes protein from adult and old rat liver.The following results were obtained : (1)The effect of glucagon on fatty acid synthesis at old rat hepatocytes was lower than that of adult rats. (2)Norepinephrine stimulation of DNA synthesis was lower at the presence of insulin and EGF (3)When the old rat hepatocytes were cultured at low cell density, the dexamethasone increased taurin conjugation of the dihydroxylated bile acids, and reversibly the hydroxylation of deoxycholate in the 6 beta and 7alpha position was decreased.These results are interesting to speculate on how old hepatocytes lose the ability to respond to the cell-surface mulator during aging. Cell-cell contact could be considered as being analogues to the interaction of hormones with surface receptors.The interaction between cells could produce an intracellular signal that is responsible for suppression of cell growth and expression of tissue-specific functions.

除增殖外，许多代谢功能受细胞密度调节，细胞生长和肝细胞特异性功能表达之间存在相互关系。另一方面，众所周知，原代培养的老年大鼠肝细胞对EGF没有正常反应。因此，我们通过改变细胞密度或添加来自成年和老年大鼠肝细胞的质膜蛋白来研究老年大鼠肝细胞中细胞生长和肝细胞特异性功能表达之间是否存在任何相互关系，得到以下结果：（1）胰高血糖素对老年大鼠肝细胞脂肪酸合成的影响低于成年大鼠。（2）去甲肾上腺素对DNA合成的刺激作用在胰岛素和EGF存在时较低（3）当老年大鼠肝细胞在低细胞密度下培养时，地塞米松增加了二羟基化胆汁酸的牛磺酸结合，可逆地，6 β和7 α位脱氧胆酸的羟基化减少。这些结果对于推测老年肝细胞如何丧失对细胞应答的能力是有趣的。老化过程中的表面模拟器。细胞与细胞之间的相互作用类似于激素与细胞表面受体的相互作用，细胞之间的相互作用可以产生细胞内信号，从而抑制细胞生长和组织特异性功能的表达。