In previous studies, we revealed the beneficial effects of verapamil and glucose-insulin-potassium solution in lung preservation. In this study, we composed a new solution (UCLA formula) containing both of these factors and compared it with Collins-Sachs solution in a canine autotransplantation model. A total of 15 dogs were used. The animals were assigned randomly to the two study groups. The left lungs of seven dogs were perfused with the UCLA formula and the left lungs of eight dogs with Collins-Sachs. Both solutions were at 4 degrees C. After 6 hours of preservation, the left lungs in both groups were autotransplanted. In the UCLA formula group, seven of seven dogs (100%) survived for the entire period of 2 weeks after the operation. In contrast, two of eight dogs in the Collins-Sachs group (25%) survived for longer than 24 hours. Pulmonary artery resistance (dyne.sec.cm-5) after transplantation was 499.8 +/- 144.8 in the UCLA group and 780.9 +/- 174.5 in the Collins-Sachs group (p less than 0.01). Pulmonary artery resistance was also ascertained with the right pulmonary artery occlusion test and showed 539.5 +/- 95.4 in the UCLA group and 1469.3 +/- 573.6 in the Collins-Sachs group (p less than 0.01). Oxygen tension (mm Hg) after lung transplantation was 74.1 +/- 10.6 in the UCLA group and 35.9 +/- 3.5 in the Collins-Sachs group (p less than 0.01). Postoperative oxygen tension with the right pulmonary artery occlusion test was measured daily for 7 days. Two survivors in the Collins-Sachs group showed significant deterioration of oxygen tension from the third postoperative day. Also, the relationship between the airway pressure and tidal volume showed a significant reduction in the Collins-Sachs group (p less than 0.01). In conclusion, the transplanted lung in which UCLA solution was used demonstrated improved lung function after 6 hours of preservation in comparison with function in lungs preserved with Collins-Sachs solution.