Intermediate normothermic hemoperfusion of rat kidneys: Functional aspects and a study into the effect of free radical scavengers

We have been able to preserve rat kidneys for 24 hours with immediate life sustaining function following transplantation into bilaterally nephrectomized recipients. Extension of preservation time to 48 hours in the same model has been possible by interposing a short (two hour) period of normothermic hemoperfusion at 24 hours. We have also reported on successful 72-hour preservation of rat kidneys with two periods of normothermic hemoperfusion interposed at 24 and 48 hours. However, extension of the preservation time was associated with a small but noticeable decline in the rate of immediate function from 100% at 24 hours to 85% at 48 hours. Also, survival of recipients of 72-hour preserved kidneys was only possible when native nephrectomy was delayed for four to seven days. To characterize the injury that limits the ability to use repeated normothermic hemoperfusion, we studied several physiological parameters of kidney function during normothermic hemoperfusion after 24 hours of cold storage of the organ. In addition, we investigated the possible contribution of free radical mediated tissue damage to the functional loss observed with multiple perfusions.