DEFECTIVE ATP-DEPENDENT BILE CANALICULAR TRANSPORT OF ORGANIC-ANIONS IN MUTANT (TR-) RATS WITH CONJUGATED HYPERBILIRUBINEMIA
DEFECTIVE ATP-DEPENDENT BILE CANALICULAR TRANSPORT OF ORGANIC-ANIONS IN MUTANT (TR-) RATS WITH CONJUGATED HYPERBILIRUBINEMIA
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DOI：
10.1073/pnas.87.9.3557
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发表时间：
1990-05-01
影响因子：
11.1
通讯作者：
ARIAS, IM
中科院分区：
文献类型：
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作者：
KITAMURA, T;JANSEN, P;ARIAS, IM
TR突变的Wistar大鼠从肝脏分泌的胆汁酸以外的有机阴离子明显少于对照大鼠。分离的正常和TR-肝细胞“双联体”，其中保留了它们之间的胆小管的荧光图像分析显示，正常肝细胞容易运输荧光胆汁酸（异硫氰酸荧光素甘胆酸盐）和非胆汁酸有机阴离子（二醋酸羧基二氯荧光素）到胆小管。TR-大鼠的肝细胞双联体也正常转运异硫氰酸荧光素甘胆酸盐，但转运羧基二氯荧光素二乙酸酯进入小管可以忽略不计。囊泡来源于从控制和TR-大鼠的肝细胞（CMV）质膜的管状结构域被用来表征35 S-标记的溴硫酞和35 S-标记的溴硫酞谷胱甘肽，这代表非胆汁酸有机阴离子的运输过程。来自正常大鼠肝细胞的CMV对这些35 S标记的化合物具有ATP和温度依赖性、可饱和的转运过程，这在来自TR-大鼠的CMV中不存在。从TR-大鼠CMV保留正常的ATP依赖的道诺霉素的运输，和免疫印迹与单克隆抗体对多药耐药基因产物，P-糖蛋白，显示正常和TR- CMV之间没有差异。这些研究表明，正常大鼠的胆小管含有一个ATP依赖的有机阴离子转运系统，这是功能上缺乏的TR-突变大鼠。TR突变大鼠的缺陷与突变型Corriedale绵羊和人的Dubin-Johnson综合征中所见的表型相似。
TR- mutant Wistar rats secrete markedly fewer organic anions other than bile acids from the liver into the bile than do control rats. Fluorescence-image analysis of isolated normal and TR- hepatocyte "doublets", which retain a bile canaliculus between them, revealed that normal hepatocytes readily transport a fluorescent bile acid (fluorescein isothiocyanate glycocholate) and a nonbile acid organic anion (carboxydichlorofluorescein diacetate) into the canaliculus. Hepatocyte doublets from TR- rats also transported fluorescein isothiocyanate glycocholate normally, but transport of carboxydichlorofluorescein diacetate into the canaliculus was negligible. Vesicles derived from the canicular domain of the plasma membrane of hepatocytes (CMV) from control and TR- rats were used to characterize the transport process for 35S-labeled bromosulphthalein and 35S-labeled bromosulphthalein glutathione, which represent nonbile acid organic anions. CMV from normal rat hepatocytes had an ATP- and temperature-dependent, saturable transport process for these 35S-labeled compounds that was absent in CMV from TR- rats. CMV from TR- rats retained normal ATP-dependent transport of daunomycin, and immunologic blots with a monoclonal antibody against the multidrug resistance gene product, P-glycoprotein, revealed no difference between normal and TR- CMV. These studies reveal that the bile canaliculus in normal rats contains an ATP-dependent organic anion transport system that is functionally absent in TR- mutant rats. The defect in TR- mutant rats is phenotypically similar to that seen in mutant Corriedale sheep and in the Dubin-Johnson syndrome in man.