Normothermic blood perfusion of isolated rabbit kidneys. III. In vitro physiology of kidneys after perfusion with Euro-Collins solution or 7.5 M cryoprotectant (VS4)

Abstract

Cryopreservation of solid organs might be possible using a mixture of cell-permeable agents, cryoprotectants (CPA), which are designed to completely preclude ice crystal formation during cooling to cryogenic temperatures. The effects of a specific prototype solution (VS4) were evaluated by normothermic blood perfusion in vitro. Rabbit kidneys were divided into three groups: untreated controls (n = 7), Euro-Collins (EC)-perfused controls (n = 6) and VS4 (4970, w/v) CPA-perfused kidneys (n = 7). After a 2-h blood perfusion, five of the seven CPA-perfused kidneys developed polyuria (0.21 mlxmin-'xg-') relative to untreated controls (0.07 mlxminp'xg-') or EC-perfused kidneys (0.06 mlxmin-'xgp'), owing to the lower reabsorption of water (34.3%), Naf (34.2%) and glucose (35.6%). Furthermore, two kidneys were non-functional with virtually no urine production. Reduced tubular function was associated with reduced oxygen consumption (3.6 versus 2.3 versus 2.0 pmolexmin-'xgp' for controls, EC-and CPA-perfused kidneys, respectively) and increased weight gain (17% versus 20% versus 30%, respectively) after blood perfusion. Therefore, the current results provide insight into both the physiological effects of VS4 and the limits of reversibility of renal pathophysiological states. Our results also indicate that in vitro monitoring of oxygen consumption and weight gain of perfused organs could be used as predictors of renal function.

Leucocyte depletion improves renal function during reperfusion using an experimental isolated haemoperfused organ preservation system

“…This is important as studies using a rabbit model demonstrated that weight gain closely paralleled impaired sodium and glucose tubular handling, and overall renal injury. Histological assessment showed this to be mainly interstitial fluid accumulation rather than cell swelling11. Despite this, the present findings provide further evidence for a vital role for leucocytes in early graft reperfusion injury that results in impaired renal function.…”

Experimental renal preservation by normothermic resuscitation perfusion with autologous blood

“…A number of experimental studies using rabbit, canine and porcine kidneys have suggested that normothermic renal resuscitation during organ preservation is more beneficial than traditional hypothermic techniques18–20. Although warm ischaemic injury and cold ischaemia can be controlled in the experimental setting20–23, in the clinical situation the logistics of organ retrieval and transfer necessitate a preliminary period of cold preservation averaging 16–18 h3.…”

Effects of arterial pressure in an experimental isolated haemoperfused porcine kidney preservation system

“…Lower pressures have been chosen because of fears that preservation at physiological pressures could fail to maintain organ integrity and induce endothelial damage15, 17, 19. Higher, more physiological pressures have been used in other models to achieve better renal function, but at the expense of limiting the duration of perfusion to a matter of a few hours13, 14, 19, 20. Most previous investigators have not justified their choice of perfusion pressure or presented data relating to the effects of different pressures in the same model.…”

“…Normothermic organ preservation is more exacting than the more traditional hypothermic techniques and this is reflected in the variable success achieved using rabbit, dog and pig kidney models13–16. The optimal conditions under which to preserve kidneys normothermically remain undetermined.…”