IMPROVEMENT OF POSTISCHEMIC KIDNEY-FUNCTION BY REPERFUSION WITH A SPECIFICALLY DEVELOPED SOLUTION (BTO1)

Reperfusion is a critical phase of organ preservation. The purpose of this study was to develop a solution specifically for postischemic kid ney reperfusion. Unilateral left normothermic kidney ischemia was indu ced for 60 minutes in two groups of micropigs. In group 1 (control pig s, n = 6) the kidney was reperfused immediately with pure blood at sys temic pressure by unclamping the renal artery. In group 2 (test animal s, n = 6) the kidney was initially reperfused with an intracellular fl ush solution enriched with solution BT01 composed of cytoprotectors (n atriuretic factor, PGl(2)), free radical chelating agents (allopurinol , mannitol), and substrates for the mitochondrial respiratory chain (a spartate, glutamate). This solution was mixed immediately before use w ith blood in a ratio of 1 :4 parts and injected into the left renal ar tery with a perfuser at a constant pressure of 60 mm Hg. After 20 minu tes, the kidney was reperfused with systemic blood for 100 minutes. Gl omerular filtration rate (GFR) was determined by measuring inulin clea rance. Kidney; blood flow was measured throughout the experiment. Afte r 120 minutes of reperfusion, the kidneys were removed for histologic examination. In the control pigs (group 1) 50% of the animals were anu ric. The ratio between GFR measured in the left kidney at the end of p erfusion and at equilibrium in the remaining animals was 0.16 +/- 0.01 . In test animals (group 2) all animals recovered diuresis. The ratio between GFR measured in the left kidney at the end of perfusion and eq uilibrium was 0.51 +/- 0.12 (p <0.001, group 2 vs. group 1). In group 2 postperfusion kidney blood flow was higher than in group 1 (63.0 ml/ min vs. 27.4 ml/min; p <0.05) because of a decrease in renal vascular resistance. Light microscopic examination of kidneys from animals in g roup 1 revealed tubular necrosis that extended to the parenchyma, with exposure of tubular interstitium. In group 2 only degenerative lesion s with edema of tubular cells and disappearance of brush borders were observed. Our findings indicate that Rushing the kidneys with BT01 sol ution mixed with blood improves postischemic kidney function by reduci ng reperfusion damage.