Evidence of free-radical-induced damage in rabbit kidneys after simple hypothermic preservation and autotransplantation.

Rabbit kidneys were stored for 24 or 48 hr at 0 degree C after single-passage vascular flush with 30 ml of cold hypertonic citrate solution or 0.9% isotonic sodium chloride solution. They were then subjected to in vitro biochemical assay for evidence of free-radical damage immediately after storage or after they had been orthotopically autotransplanted and reperfused with blood in vivo for 60 min. Kidney homogenates were incubated at 37 degrees C and assayed for fluorescent conjugated Schiff bases as indicators of lipid peroxidation, as well as for superoxide dismutase activity and reduced and oxidized glutathione. In kidneys flushed with hypertonic citrate, no evidence of peroxidation could be detected immediately after storage for 24 or 48 hr. However, after in vivo reperfusion significantly more peroxidation (P less than 0.01) was evident. Storage in isotonic saline solution produced still higher levels of peroxidation damage whether reperfused or not (P less than 0.001). Schiff base formation was inversely proportional to the reduced and oxidized glutathione levels measured. No changes in superoxide dismutase levels could be detected. It is concluded that lipid peroxidation is important during cold ischemia but most damage occurs during the 60-min of reperfusion in vivo immediately after transplantation.