PROTECTION OF ISOLATED LUNG FROM REPERFUSION INJURIES BY RINSING WITHHIGH COLLOIDAL OSMOTIC SOLUTION WITH DEFEROXAMINE

We examined the efficacy of rinsing isolated lungs subjected to prolon ged hypothermic storage with a high colloidal osmotic pressure solutio n prior to ex vivo blood reperfusion in order to preserve physiologic functions, suppress peroxidation of mitochondrial membranes, and inhib it infiltration of neutrophils. Isolated rabbit lungs were flushed wit h a Rinse-1 solution (289 mOsm/kg H2O) to remove remaining blood and i mmersed in physiologic saline at 8 degrees C for 24 hr. The control gr oup received blood reperfusion immediately after storage; the Rinse-1 group was rinsed with Rinse-1 solution before blood reperfusion and th e Rinse-2 group with Rinse-2 solution (312 mOsm/kg H2O) including defe roxamine. Reperfused blood was passed through an artificial membranous lung to reduce oxygen tension (P-O2) to the venous level, and time-de pendent changes in airway pressure (AWP), pulmonary artery pressure (P AP), and PO2, as a measure of gas-exchange capability were examined. W e estimated the lipid peroxide level in mitochondrial membranes as thi obarbituric acid-reactive substances (TBARS), i.e., malonedialdehyde, and neutrophil infiltration into lung tissue by measuring myeloperoxid ase activity after 60 min of blood reperfusion. The P-O2 was significa ntly higher in both rinsed groups compared with the control, while nei ther AWP nor PAP was significantly different in the three treatment gr oups. Both mitochondrial TEARS and myeloperoxidase activity were signi ficantly higher in the control group compared with either rinsed group . These results indicate that rinsing stored lungs with a solution of high colloidal osmotic pressure prior to blood reperfusion was effecti ve in preserving physiologic function and inhibiting neutrophil infilt ration. Addition of deferoxamine was markedly effective in reducing TE ARS formation and lessening reperfusion injury of stored lungs.