l‐Arginine‐enriched preservation solution decreases ischaemia/reperfusion injury in canine kidneys after long‐term cold storage

Background. Kidneys stored hypothermically for transplantation show varying degrees of tissue injury, depending on the duration of preservation. The causes of injury are not entirely clear. We investigated the quality of renal functional recovery in canine kidneys after 72 h hypothermic preservation in custodiol solution or custodiol solution plus l‐arginine. Methods. Kidneys obtained from mongrel dogs, weighing 18–25 kg, were subjected to 72‐h cold ischaemia after flushing. Animals were divided into two groups (n=18/group). A flush solution of either custodiol solution or custodiol solution plus l‐arginine 1 mmol/l was used for each group. After 72‐h cold storage all animals had a contralateral nephrectomy, and autotransplantation was performed to external iliac artery and vein. Survivals were evaluated at 3 days. Results. Renal damage was assessed by kidney function tests, serum creatinine (SCr), blood urea nitrogen (BUN) and light histology. Malondialdehyde (MDA) was measured as an index of lipid peroxidation. SCr and BUN (24, 48 and 72 h) were significantly different from the control and l‐arginine groups. Histological damage was less in the l‐arginine group. MDA levels were significantly different with the lower levels in the l‐arginine group. Conclusions.On the basis of these data, we concluded that exogenous l‐arginine (a substrate for NO synthesis) has a beneficial and protective effect on long‐term (72 h) hypothermic ischaemical damage in canine kidneys.