The intent of the research project proposed herein is to refine and enhance an existing method of renal preservation for transplantation. The method empoys a single perfusion with a cold hyperosmolar, intracellular electrolyte solution followed by storage in the same solution for 24 to 72 hours. The solution must be refined to only relevant ionic components, and extraneous chemicals causing precipitation must be identified and eliminated. The effect of the solution may be enhanced by pre-treatment of the donor animal with steroids or Allopurinol, and/or by possible inclusion of these pharmacological additives to the solution. The effect of the solution may be further enhanced by utilizing initial oxygenation and/or intermittent re-perfusion of the kidney during the period of preservation. An additional effort will be devoted to identifying those specific energy substrates utilized during normothermic renal metabolism. The enzyme dynamics of providing substrates during hypothermic preservation will be extensively studied and applied.