THE EFFECT OF TECHNICAL CONDITIONS AND STORAGE MEDIUM COMPOSITION ON THE PHOSPHOMONOESTERS TO INORGANIC-PHOSPHATE RATIO DETERMINED BY P-31 NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY IN RABBIT KIDNEY

Using P-31 nuclear magnetic resonance spectroscopy, we compared the st ate of the high-energy phosphates in rabbit kidneys stored at 4-degree s-C for 24 hr with 3 different solutions: Ringer (Rg), University of W isconsin (UW), and EuroCollins (EC) solutions. We found the highest ph osphomonoester/inorganic phosphate (MP:Pi) ratio in the group of kidne ys stored in the Rg solution (Rg, 0.93 +/- 0.04; UW, 0.36 +/- 0.02; EC , 0.28 +/- 0.02). This medium has been demonstrated in previous physio logical studies to give poor results in terms of organ preservation co mpared to the solutions that mimic the ''intracellular'' fluid, such a s the EC and UW solutions. Because the commonly used cold storage solu tions contain phosphates, which superimpose on the intracellular Pi an d, thus, can distort the results, we attempted to eliminate the contam inating solution around the kidney and in the vasculature by flushing the kidney with a phosphate-free solution (Rg). The MP:Pi ratio increa sed in the UW and EC groups (UW, 0.82 +/- 0.04; EC, 0.64 +/- 0.04) in identical proportion in the 2 groups. It remained highest in the Rg gr oup (1.02 +/- 0.03). Comparisons of data before and after flush showed that external phosphate contamination was not predominant. There was no equilibrium in phosphate distribution between intra- and extracellu lar spaces at 24 hr of storage. We conclude that the validity of the M P:Pi ratio, as a viability index of renal transplant, might have to be restricted to comparisons of kidneys preserved in the same storage co nditions. Therefore, it would be necessary to establish normal and pat hological values of this ratio for each cold storage solution.