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Updated: Jun 21, 2026
Liver Cold Storage and Transplantation in the Cold-Adaptive Daurian Ground Squirrels
Published on: July 3, 2025
Preservation solutions alter Mrp2-dependent bile flow in cold ischemic rat livers
Shaoguang Sui1, Atsushi Kudo, Makoto Suematsu
1Department of Hepatobiliary-Pancreatic Surgery, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Background:
Previously, decreased organic anion transport through multidrug resistance protein 2 (Mrp2) was observed without any notable cell lysis, even when the livers were stored for 8 hours in University of Wisconsin solution (UW). The aim of this study was to examine the bile flow and its constituents, markers of graft dysfunction without necrosis in cold ischemic livers, using the following preservation media: UW, ET-Kyoto solution (ET-K) and histidine-tryptophan-ketoglutarate solution (HTK).
Materials And Methods:
Rat livers were stored at 4 degrees C for 8 hours in the preservation media, and reperfused to collect the bile and determine their constituents. Glycyrrhizin (GL) and/or glutathione (GSH) were added to the media as necessary. The transport efficiency of Mrp2 was assessed by the biliary excretion of 5-carboxyfluorescein (CF), a fluoroprobe excreted from Mrp2. The Intracellular distribution of Mrp2 was determined by immunostaining.
Results:
Livers stored for 8 hours exhibited significantly decreased bile production and biliary glutathione (GSH) levels without notable cell lysis. CF excretion was significantly delayed in all solutions. However, these markers were remarkably improved by the redistribution of Mrp2 from the cytoplasm to the canalicular membrane, when the livers were exposed to UW in the presence of GL. Moreover, livers exposed to the Kyoto and HTK solutions increased their bile production and organic anion transport in the presence of GL and GSH.
Conclusion:
These results suggest that the addition of GL and GSH to preservation solutions improves bile production and biliary organic anion transport by increasing Mrp2 localization to the bile canaliculi in post-cold ischemic livers. (248 words).
Insights
Adding glycyrrhizin and glutathione to preservation solutions improves bile production and organic anion transport in cold-stored livers by enhancing multidrug resistance-associated protein 2 (Mrp2) function. This supports graft viability without causing cell lysis.
Area of Science:
- Hepatology and Transplant Surgery
- Organ Preservation and Perfusion
- Biomarkers of Graft Dysfunction
Background:
- Cold ischemia impairs liver graft function, specifically decreasing organic anion transport via multidrug resistance-associated protein 2 (Mrp2).
- Previous studies noted Mrp2 dysfunction without significant cell lysis after 8-hour cold storage in University of Wisconsin (UW) solution.
- Graft dysfunction markers in cold-stored livers require investigation across different preservation media.
Purpose of the Study:
- To evaluate bile flow and constituents in cold-ischemic rat livers preserved in UW, ET-Kyoto (ET-K), and histidine-tryptophan-ketoglutarate (HTK) solutions.
- To assess the impact of glycyrrhizin (GL) and glutathione (GSH) on Mrp2 function and bile transport.
- To identify strategies for improving graft viability post-cold ischemia.
Main Methods:
- Rat livers were cold-stored for 8 hours in UW, ET-K, or HTK solutions.
- Bile production and constituents were analyzed post-reperfusion.
- Multidrug resistance-associated protein 2 (Mrp2) transport efficiency was measured using 5-carboxyfluorescein (CF) biliary excretion.
- Intracellular Mrp2 distribution was assessed via immunostaining.
Main Results:
- All preservation solutions led to decreased bile production and biliary glutathione (GSH) levels without cell lysis.
- Biliary excretion of CF, a marker for Mrp2 transport, was significantly delayed in all tested solutions.
- Addition of GL to UW solution, and GL with GSH to ET-K and HTK solutions, improved bile production and CF transport.
- These improvements correlated with enhanced Mrp2 localization to the canalicular membrane.
Conclusions:
- Glycyrrhizin (GL) and glutathione (GSH) significantly enhance bile production and organic anion transport in post-cold ischemic livers.
- The addition of GL and GSH promotes Mrp2 redistribution to the canalicular membrane, restoring transport function.
- These findings suggest a promising strategy for improving liver graft quality and outcomes after cold storage.
