The Beneficial Effect of Intermediate Normothermic Perfusion During Cold Storage of Ischemically Injured Kidneys. A Study of Renal Nucleotide Homeostasis During Hypothermia in the Dog

The effect of simple cold storage on ice with or without preceding warm ischemic injury on the energy metabolism and posttransplant viability of canine kidneys was examined in the present study. In addition, we investigated the possible beneficial effect of an intermediate normothermic perfusion half-way through the storage period on the preservation of ischemically injured kidneys. Thirty mongrel dogs were allocated to 5 experimental groups. In groups I and II kidneys were simply stored on ice for 24 and 48 hr, respectively. In groups III and IV kidneys were additionally subjected to 30 min warm ischemia before storage. In group 5 kidneys were treated as in group IV, but halfway through the storage period an intermediate normothermic ex-vivo perfusion was performed. The effect of these procedures on renal viability was tested by autologous reimplantation of the kidneys. During implantation the contralateral kidney was immediately removed. In group I all animals survived, whereas in group IV none of the animals survived. In groups II, III, and V, 2 of 6, 1 of 6, and 3 of 6 animals survived, respectively. The relationship, if any, between poststorage renal viability and the tissue levels of adenine nucleotides, guanine nucleotides, IMP, and purine degradation products was assessed by measuring the content of these metabolites in tissue specimen of the renal cortex, on which biopsies were done at various intervals during the experimental procedures. After an initial drop of about 30% in the content of adenine and guanine nucleotides and an increase in IMP, these values remained constant during 48 hr of cold storage. In contrast to kidneys stored for 24 hr, reimplantation of kidneys stored for 48 hr resulted in a significant decrease of adenine nucleotides following 60 min of in vivo reperfusion. Warm ischemia for 30 min prior to cold storage lead to lower initial nucleotide levels at the start of the storage period. During the first 24 hr nucleotide levels did not change, but a further decrease was observed during the following 24 hr of storage. Reimplantation after 24 hr of storage resulted in an additional decrease in the content of nucleotides. This poststorage decrease was absent after 48 hr of cold storage. Intermediate normothermic perfusion halfway through the storage for 48 hr significantly prevented the drop in the nucleotide content observed during the last 24 hr of storage in the corresponding control group. This nucleotide-sparing effect did not increase the level of nucleotides at the end of 60 min of reperfusion following reimplantation.(ABSTRACT TRUNCATED AT 400 WORDS)