Effect of phentolamine on perfusate flow characteristics during renal preservation.

Despite continuing improvements in the technique of hypothermic perfusion of cadaver kidneys, some renal transplants do not function after such preservation for any apparent reason. The presence of shock, sepsis, low perfusion states, or hypoxia in the cadaver donor has profound effects on the perfused cadaver kidney, due partly to catecholamine-induced intrarenal vasoconstriction [2]. In addition, there is evidence that the vasoconstriction persists after transplantation which may lead to acute renal failure 111. Recently, Miller et al. have shown the salutary effects that an a-adrenergic blocking agent, phentolamine, has on the flow characteristics of the perfused kidney, both experimentally and clinically [7]. These investigators suggest that the post-transplantation function of cadaver kidneys might be improved using intraarterial phentolamine during perfusion. Several investigators [5, 61 have shown experimentally that the intrarenal distribution of perfusate during isolated, hypothermic perfusion is adversely affected by hypoxia in the donor animal, probably due to intrarenal vasoconstriction induced by circulating catecholamines. The characteristic pattern is a decreased percentage of perfusate flow to the renal cortex of varying degree, depending upon the condition of the donor and the warm ischemic time prior to perfusion [6]. However, the effects of a-adrenergic blockage with phentolamine on the intrarenal distribution of perfusate in the preserved kidney have not been extensively evaluated. This study is an attempt to define the intrarenal distribution of perfusate in the hypothermic preserved kidney removed from hypoxic donor animals. In addition, the effects of phentolamine on the intrarenal distribution of perfusate were investigated.