[Gadoxetic disodium-enhanced MRI to characterize T1 relaxation values and expression level of organic anion transporters and multidrug resistance protein on hepatocyte surface membrane of normal C57BL/6 mice].

Objective: The characteristics of T1 relaxation values and the expression levels of organic anion transport system (OATP) and multidrug resistance protein carrier (MRP) on hepatocyte surface membrane were quantitatively studied to evaluate liver function in normal C57BL/6 mice with gadoxetic disodium-enhanced MRI. Methods: Ten 6-weeks-old, normal C57BL/6 mice were included in this study. Gadoxetic disodium- enhanced MRI examination was performed. Longitudinal relaxation time images before and 20 min after contrast injection (hepatobiliary-specific phase) were acquired. T1-relaxation time, T1 relaxation time decline rate (△T) and rapid initial enhancement slope percentage in the first-pass study of the liver parenchyma before and after administration of gadoxetate disodium were measured. Liver parenchyma specimens were detected by Western blotting and the values ​​of OATP1, MRP2, and MRP3 were recorded. Statistical results were expressed in mean. Results: The mean T1 relaxation time of 10 normal C57BL/6 mice before and after enhancement was 659.13 ± 24.07, and 408.87 ± 27.21 ms. The mean T1 relaxation time decline rate and rapid initial enhancement slope percentage in the first-pass study was 37.12% ± 4.95% and 4.14% ± 0.96% ms. Furthermore, the mean value of OATP1, MRP2 and MRP3 were 29 952.1 ± 11 475.2, 34 376.4 ± 33 228.4 and 357 308.9 ± 64 646.5. Conclusion: T1-relaxation values, T1 relaxation time decline rate and rapid initial enhancement slope percentage in the first-pass study before and after gadoxetic disodium-enhanced MRI were determined in normal C57BL/6 mice as well as quantitative values of OATP1, MRP2 and MRP3 at the molecular level on the hepatocyte surface membrane were helpful for liver injury model with control study.目的： 定量研究正常C57BL/6小鼠钆塞酸二钠增强磁共振检查T1弛豫值特征及肝细胞膜表面相关有机阴离子转运系统（OATP）和多耐药蛋白载体（MRP）的表达水平，用于进一步肝功能的评价。 方法： 10只6周龄正常C57BL/6小鼠纳入研究，行钆塞酸二钠增强磁共振动态检查，并在对比剂注射前及注射后20 min（肝胆特异期）获得纵向弛豫时间图。测量计算肝实质的钆塞酸二钠增强前后的T1弛豫时间、T1弛豫时间下降率（△T）以及首过快速上升期中的增强斜率百分比。肝实质标本行蛋白质印迹法检测，记录OATP1、MRP2、MRP3值。统计结果用平均值表示。 结果： 10只正常C57BL/6小鼠增强前T1弛豫时间平均值为（659.13±24.07）ms，增强后T1弛豫时间平均值较增强前缩短，为（408.87±27.21）ms；T1弛豫时间下降率平均值为37.12%±4.95%；首过快速上升期中的增强斜率百分比为4.14%±0.96%。10只正常C57BL/6小鼠OATP1的值为29 952.1±11 475.2、MRP2的值为34 376.4±33 228.4及MRP3的为357 308.9±64 646.5。 结论： 明确正常C57BL/6小鼠钆塞酸二钠增强磁共振检查增强前后T1弛豫值、T1弛豫值的下降率、首过快速上升期中的增强斜率百分比，以及肝细胞膜上分子水平OATP1、MRP2、MRP3的定量值，有助于与肝损伤模型做对照研究。.