In Japan, we have not been able to perform a heart transplantation for more than 20 years, because a concept of brain death has not been approved ethically or legally. We examined whether cadaver hearts could be used as grafts for heart transplantations, and which of UW solution (UW) and Euro-Collins solution (EC) was more suitable for cadaver heart preservation. Adult Sprague-Dawley rats were divided into 4 groups of 5 each. In Group I, the hearts were harvested under beating. In the other groups, cardiac arrest was derived by exsanguination, and cardiectomy were performed after 15 (Group II, III) or 30 (Group IV) minutes from flattening of arterial blood pressure. Soon after the cardiectomy, UW (10 ml/kg) was infused in Group I, II and IV, and EC (10 ml/min) was infused in Group III. After simple cold storage (0 degree C) for 30 minutes, oxygenated KHB solution (37 degrees C) were perfused in Langendorff mode for 30 minutes, and were switched over to working mode. Aortic pressure and cardiac output were measured for 30 minutes. Following to the measurements, glutaraldehyde was perfused and studied microscopically. All cases could be switched over to working mode in group I and II, but 2 cases in Group III and 4 cases in IV could not make a pressure enough to keep working mode. In hemodynamic and histological study, there were no significant differences between Group I and II, but Group III and Group IV were clearly inferior to Group I and II. In cadaver heart preservation, UW solution was superior to EC solution.(ABSTRACT TRUNCATED AT 250 WORDS)