Pre-Hepatectomy Assessment of Bile Transporter Expression by Gadoxetic Acid-Enhanced MRI in a Rat Model of Liver Cirrhosis

ABSTRACTBackground: Gadoxetic acid is a liver-specific intravenous T1 magnetic resonance (MR) contrast agent that is excreted via the hepatobiliary system. We hypothesize that hepatocyte expressions of bile transporters (OATP1 and MRP2) correlate with dynamic profile of Gadoxetic acid enhanced (GE)-MR imaging (MRI). Methods: Two groups of rats, control (n = 6) and cirrhosis (n = 12), received gadoxetic acid enhanced MRI followed by 70% hepatectomy. The change in MR signal intensity from the baseline before the contrast injection (ΔSI) was analyzed every minute for 30 min. Dynamic signal intensity retention ratio (DSR) was defined as the mean ΔSI of the third 10-minmin period divided by the first 10-minmin period. Real-time PCR was utilized to quantify mRNA expressions. Results: Compared to the control, cirrhosis group demonstrated lower mRNA levels of OATP1 (0.038 ± 0.020 vs. 0.232 ± 0.0979; p = 0.004), MRP2 (0.201 ± 0.084 vs. 0.7567 ± 0.254; p = 0.002), and OATP1/MRP2 mRNA ratio (0.193 ± 0.065 vs. 0.342 ...