Effects of Euro-Collins, University of Wisconsin, and new extracellular-type trehalase-containing Kyoto solutions in an ex vivo rat lung preservation model

Background. We have previously reported the effects of trehalose-based extracellular-type Kyoto (ET-K) solution in lung preservation, Now, we have developed a new ET-K solution by adding three substances-N-acetyl cysteine, dibutyryl cyclic AMP, and nitroglycerin, to ET-K solution, We studied the effects of new ET-K solution in lung preservation, and compare it with Euro-Collins (EC) and University of Wisconsin (UW) solutions using an ex vivo rat reperfusion model. Methods. The perfusion circuit was initiated by 30 ml of fresh mixed venous blood obtained from three haparinized rats. By means of a double-head roller pump, the blood passed from the venous blood reservoir through the pulmonary artery to be perfused in the examined lung. The lung effluent was returned at the same flow rate to the deoxygenator fresh lung. Four experimental groups were allocated, In group 1 (fresh group, n=6), lung was flushed with saline and reperfused immediately, In the other groups (group 2: new ET-K group, n=6; group 3: UW group, n=6; and group 4: EC group, n=6), lung was flushed with the new ET-K and prostanglandin E1 (PGE1), UW and PGE1, and EC and PGE1, respectively. After 17-hr preservation, the preserved lung was reperfused. Results. In all six animals of the EC group, ventilation of the experimental lung was discontinued at 20 min after reperfusion because of the exudate in the endotracheal tube that resulted from pulmonary edema. The shunt fraction, pulmonary arterial pressure, and peak inspiratory pressure in the new ET-K and UW groups were significantly better than those in the EC group, but were almost equal to those in the fresh group. Conclusion. The postpreservation pulmonary functions with the new ET-K solution were better than those with, the EC solution, and were equal to those with the UW solution. This new solution is expected to contribute to the increase in donor lungs for clinical lung transplantation. In addition, this ex vivo rat reperfusion model is simple and highly reliable, and can be widely used in the studies of pulmonary preservation.