Relative importance of prostaglandin/cyclic adenosine monophosphate and nitric oxide/cyclic guanosine monophosphate pathways in lung preservation

Background. Modulation of vascular tone and platelet and neutrophil function through the prostaglandin/cyclic adenosine monophosphate or nitric oxide/cyclic guanosine monophosphate pathway can benefit lung graft function. The relative importance of these pathways is unclear. Methods. Rat lung grafts (5 per group) were studied in an ex vivo reperfusion model. Group I grafts were pretreated with prostacyclin (20 ng · kg−1 · min−1), flushed with cold Euro-Collins solution containing prostacyclin (200 μg/L), and reperfused immediately for 1 hour. Group II grafts were similarly procured but were stored at 4°C for 6 hours before reperfusion. In group III, no prostacyclin therapy was used; instead, the nitric oxide donor glyceryl trinitrate (0.1 mg/mL) was added to the flush/storage solution, and the grafts were stored for 6 hours. Results. Group II grafts performed poorly compared with those in group I, with substantial deterioration of oxygenation and blood flow and elevation of pulmonary artery pressure, peak airway pressure, and wet to dry weight ratio. In contrast, graft function in group III was similar to that in controls. Conclusions. Lung graft integrity after storage in Euro-Collins solution was better preserved by glyceryl trinitrate than by prostacyclin in this model.