ASSESSMENT OF PURINE METABOLISM IN HUMAN RENAL-TRANSPLANTATION

Cortical levels of nucleotides and their degradation products from 42 transplanted human kidneys have been studied. Biopsies were performed during renal harvesting just before cooling, at the end of cold storag e, and following reinstallment of renal blood circulation. ATP levels fell, and AMP and degradation products (inosine monophosphate [IMP], i nosine, adenosine, and hypoxanthine) increased during cold storage and returned to near-normal values 30 min after recirculation. The major degradation product found was hypoxanthine, indicating very poor xanth ine oxidase activity in human kidneys. The sum of adenine nucleotides (ATP+ADP+AMP) did not significantly decrease after cold storage, but a denylate energy charge (ATP+1/2ADP/ATP+ADP+AMP) was reduced to half, b eing recovered in implanted kidneys. The sum of adenine nucleotides wa s significantly reduced after implantation. The rate of acute tubular necrosis was higher in kidneys preserved for more than 30 hr. Kidneys with acute tubular necrosis had significantly lower levels of the tota l pool of adenine nucleotides at reperfusion, but there was no correla tion between incidence of acute tubular necrosis and ATP or other meta bolite levels in the kidneys before or during cold preservation. The s uccess of human kidney transplantation does not seem to depend only on the pool of residual nucleotides at the end of cold storage but on ot her factors that determine the ability of the cell to recover a normal energy state after reperfusion.