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Bile acid uptake mechanism of hepatocyte membrane in primary cultured hepatocyte

原代培养肝细胞肝细胞膜摄取胆汁酸的机制

基本信息

批准号：
60570322
负责人：
IKAWA Shiro
金额：
$ 0.9万
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：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60570322/
关键词：
Bile acid uptake Primary culture Rat hepatocyte Estradiol-glucuronide Bile acid metabolism <Na^+> , <K^+> -ATPase 【Na^+】,【K^±】ATPase

项目摘要

Bile acid uptake mechanism of the hepatocytye membrane was studied using primary cultured rat hepatocytes. Bile acid profiles of intra or extrahepatocyte, namely the hepatocyte or the culture medium were used as the indicator showing the biochemical functions of the hepatocyte.Bile acid profiles of primary cultured rat hepatocytes were kept qualitatively and quantitatively nearly constant during 19-hr to 72-hr incubation. At these incubation periods, bile acid profiles of the incubation medium were most similar to those of the hepatic bile acids of the hepatic bile obtained about 11 hrs after bile duct canulation, regarded as the wash-out point at which point, the bile contains only primary bile acids. The present studies were carried out using the primary cultured rat hepatocytes obtained after 24-hr incubation.The hepatocytes pretreated with lidocaine hydrochloride of rifamycin reduced bile acid uptake by about 30 to 50 % as compared with the control. On the other hand, the simultane … More ous addition albumin with the abovementioned drugs increased bile acid uptake dose-dependently. These facts suggest strongly that the hepatocyte membrane has a bile acid receptor sharing with albumin or these drugs. In the hepatocytes cultured with insulin alone or both dexamethasone and insulin the latter produced and extreted much more taurine-conjugated bile acids. Estradiol-17 <beta> -glucuronide ( <E_2> -17G ) induced the cholestasis-like state: The decrease of intracellular cAMP, 5'-Nase activity and taurine-conjugated bile acids and the marked increase of sulfated bile acids, especially lithocholic and chenodeoxycholic acids were observed, while dexamethasone improved these changes to the normal levels. It seems likely that <E_2> -17G affects endoplasmic reticulumn and peroxisomes in the hepatocyte and causes an alternative pathway of bile acid biosynthesis influencing cholic acid: CoA ligase and 12 <alpha> -hydroxylase and these changes resuly in inhibition of <Na^+> -dependent bile acid reflux followed by the decrease of cAMP-dependent <Na^+> , <K^+> -ATPase, finally induce intrahepatic cholestasis.Further studies on purification and kinetics of a bile acid receptor on the hepatocyte membrane are required and some are under progress. Less

用原代培养的大鼠肝细胞研究了肝细胞膜摄取胆汁酸的机制。原代培养的大鼠肝细胞在培养19 ~ 72小时期间，胆汁酸浓度在定性和定量上基本保持不变，胆汁酸浓度在肝细胞内或肝细胞外（即肝细胞或培养液）均能作为反映肝细胞生化功能的指标。在这些孵育期，孵育培养基的胆汁酸谱与胆管插管后约11小时获得的肝胆汁的肝胆汁酸谱最相似，胆管插管后约11小时被视为洗脱点，此时胆汁仅含初级胆汁酸。本研究采用原代培养的大鼠肝细胞，经24小时孵育后，经利福霉素或盐酸利多卡因预处理的肝细胞，其胆汁酸摄取量比对照组减少约30 ~ 50%。另一方面， ...更多信息白蛋白与上述药物联合使用可剂量依赖性地增加胆汁酸摄取。这些事实有力地表明，肝细胞膜具有与白蛋白或这些药物共享的胆汁酸受体。在胰岛素单独或地塞米松和胰岛素共同培养的肝细胞中，后者产生和排出更多的牛磺酸结合胆汁酸。雌二醇-17<beta>-葡萄糖醛酸苷（<E_2>-17 G）诱导胆汁淤积样状态：观察到细胞内cAMP、5 '-Nase活性和牛磺酸结合胆汁酸减少，硫酸化胆汁酸显著增加，尤其是石胆酸和鹅去氧胆酸，而地塞米松将这些变化改善至正常水平。-17 <E_2>G可能影响肝细胞中的内质网和过氧化物酶体，并导致胆汁酸生物合成的另一条途径影响胆酸：CoA连接酶和12<alpha>-羟化酶，这些变化导致<Na^+>依赖性胆汁酸反流的抑制，随后cAMP依赖性<Na^+>，<K^+> -ATP酶，对肝细胞膜上胆汁酸受体的纯化和动力学的进一步研究是必要的，有些正在进行中。少