Abstract
Reperfusion injury is a large problem in the early stage after lung transplantation. Its prevention by Urinary Trypsin Inhibitor (UTI) was evaluated experimentally. Warm ischemic models were made with left lungs of adult mongrel dogs. The time for the warm ischemic procedure was set at 2 hours, and the lungs were reperfused for 2 hours. The experimental group was divided into a control group and a UTI group, the latter received 10, 000 units/kg of UTI from 30 minutes before the termination of warm ischemia to the termination of reperfusion. In the control group, the pulmonary vascular resistance and the wet and dry weight ratios (W/D ratio) increased significantly, and a thickened interstitium and infiltration of neutrophils were observed histologically after the reperfusion ended. Only two of the five dogs in the survival experiment survived for more than 7 days. In the UTI group, the pulmonary vascular resistance increased slightly, but the W/D ratio did not increase significantly, and there were no histological abnormalities at the termination of reperfusion. All five dogs survived for more than 7 days in the survival experiment. These results indicate that UTI significantly attenuates reperfusion injury, perhaps by inhibiting neutrophil protease.
