Liver preservation for transplant. Evaluation of hepatic energy metabolism by 31P NMR.

31P NMR spectroscopy proved to be an excellent, dynamic, nondestructive method for assessing the liver during cold flush and pulsatile perfusion experiments. 31P NMR spectroscopy was used to measure ATP decay, inorganic phosphate appearance, and phosphate chemical shift in the excised mouse livers subjected to cold and warm ischemia. Cold flush followed by cold preservation in saline, Krebs-Henseleit buffer, or Collins' solution showed that Collins' solution resulted in the slowest ATP decay. In temperature-controlled experiments (5 degrees -37 degrees C), ATP decay was much slower with lower temperature. In separate pulsatile perfusion experiments with oxygenated Krebs-Henseleit buffer, hepatic ATP was unchanged for at least 6 hr at 20 degrees C. At 37 degrees C, the NMR spectrum showed changes in the diphosphoesters region, but the ATP remained stable during the 6-hr perfusion. These studies suggest that for long periods of liver preservation, an adequate perfusion method should be developed.