Role of renal and inteslinal ABC transporters during cholestatic liver disease

背景与目的：多药耐药蛋白2(MRP2)、MRP3、胆盐输出泵(BSEP)和Mdrlb已被鉴定为胆汁酸或药物转运蛋白。本研究旨在探讨ABC转运蛋白在胆汁淤积中的表达。方法：实验1：大鼠胆管结扎或假手术。分别于术后24、72小时采血、取肝、取小肠。实验二：大鼠分为四组：1)对照组。2)薯蓣皂苷元组(饲喂薯蓣皂苷元[1%(wt/wt)]，连续7d)。3)乙基雌二醇组(给予乙炔雌二醇5 mg/(kg·d)，连续5天)。4)薯蓣皂苷元-乙炔雌二醇组(给予乙炔雌二醇组和薯蓣皂苷元组)。治疗后取血、胆汁、肝、肠。逆转录-聚合酶链式反应分析脂类和胆汁酸代谢相关基因的表达。结果：胆管结扎后24小时，肠组织中MRP2基因的表达显著降低，72小时后恢复正常。BDL后大鼠肠道MRP3基因表达无明显变化。与对照组相比，薯蓣皂苷元和薯蓣皂苷元-乙烯雌二醇组大鼠肠道mrp2基因的表达显著增加。4组大鼠肠道组织中MRP3基因表达差异无统计学意义。与对照组相比，D、EE和DE组大鼠肝脏MRP3mRNA表达显著增加(分别为对照组的531%、321%和1160%，p&lt；0.01)。结论：1)胆管结扎不仅影响肝脏，还影响肠道组织中MRP2的表达。2)肠道mrp2基因表达水平受管腔因素(如薯蓣皂苷元饲喂)的调节。3)薯蓣皂苷元可增强乙炔雌二醇所致的胆汁淤积作用，肝组织mrp3基因表达水平的升高可能影响这种作用。

Background and Aim : Multidrug resistance protein 2 (Mrp2), Mrp3, bile salt export pump (Bsep) and Mdrlb have been identified as bile acid or drug transporter The purpose of this study is to evaluate hepatic, renal and intestinal ABC transporter expressions during cholestasis. Methods : Experiment 1 : Rats were subjected to bile duct ligation or sham operation. Blood, liver and small intestine were obtained 24 and 72 hours after operation. Experiment 2 : Rats were subjected to four groups as follows : 1)Control group. 2)Diosgenin group (fed with diosgenin in diet [1%(wt/wt)] for seven days). 3)Ethinyl estradiol group (recieved ethinyl estradiol (5mg/kg daily) for five days). 4)Diosgenin-ethinyl estradiol group (received ethinyl estradiol and diosgenin). After treatment, blood, bile, liver and intestine were obtained. The mRNA related to lipid and bile acid metabolism was analyzed by RT-PCR. Results : Intestinal Mrp2 mRNA expression remarkably decreased 24 hours after bile duct and recovered 72 hours after bile duct ligation. Intestinal Mrp3 mRNA expression did not change after BDL. Intestinal Mrp2 mRNA expression was remarkably increased in Diosgenin and Diosgenin-ethinyl estradiol groups in comparison with the control group. There were no significant differences in intestinal Mrp3 mRNA expression among the four groups. Hepatic Mrp3 mRNA expression was remarkably increased in the D, EE and DE groups in comparison with the control group (531 %, 321% and 1160 % of control, respectively, p<0.01). Conclusion : 1)Bile duct ligation affects not only hepatic but also the intestinal Mrp2 expressions. 2)Intestinal Mrp2 mRNA level is regulated by factor in the lumen (e.g. diosgenin feeding). 3)Cholestasis by ethinyl estradiol treatment was enhanced by diosgenin and the increase in hepatic Mrp3 mRNA level may affect the enhancement.