Assessment of liver graft function after cold preservation using 31P and 23Na magnetic resonance spectroscopy

We investigated the functional damages of the cytoplasm and the cell membrane of liver grafts in male Wister Kyoto rats after 24-hr and 48-hr cold preservations using the University of Wisconsin solution in vitro. Fructose (10 mM) or NH4Cl (50 mM) was added to the perfusate, and synthesis of fructose-1-phosphate (F-1-P) and Na- and H-ion transports through the cell membrane were evaluated by magnetic resonance spectroscopy (MRS), 31P-MRS and 23Na-MRS. After 30 min of reperfusion, beta-ATP/(inorganic phosphate: Pi) of the 48-hr preserved group was significantly lower than the control group and the 24-hr preserved group. The changes of F-1-P in the control group and the 24-hr preserved group were almost the same, but F-1-P synthesis was lower in the 48-hr preserved liver than those of the other groups. Intracellular pH began to drop after the cessation of NH4Cl loading, and then it recovered to the preloading level. At the same time Nain+ was increased in the control group. However, in the other two groups, the increasing rates of Nain+ were lower, and the recoveries of Nain+ were less. In conclusion, the function of cell membrane was more fragile than that of mitochondria and cytoplasmic sugar metabolism in the liver graft.