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 fu nction through the prostaglandin/cyclic adenosine monophosphate or nit ric oxide/cyclic guanosine monophosphate pathway can benefit lung graf t function. The relative importance of these pathways is unclear. Meth ods. Rat lung grafts (5 per group) were studied in an ex vivo reperfus ion model. Group I grafts were pretreated with prostacyclin (20 ng . k g(-1). min(-1)), flushed with cold Euro-Collins solution containing pr ostacyclin (200 mu g/L), and reperfused immediately for 1 hour. Group II grafts were similarly procured but were stored at 4 degrees C for 6 hours before reperfusion. In group III, no prostacyclin therapy was u sed; instead, the nitric oxide donor glyceryl trinitrate (0.1 mg/mL) w as added to the flush/storage solution, and the grafts were stored for 6 hours. Results. Group II grafts performed poorly compared with thos e 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 af ter storage in Euro-Collins solution was better preserved by glyceryl trinitrate than by prostacyclin in this model.