Treatment of ischemia-reperfusion injury after lung transplantation with ulinastatin in a left lung allograft model of rat

Purpose To investigate the beneficial effects of a protease inhibitor,ulinastatin(UTI),on ischemia reperfusion lung injury,by using an orthotopic single left lung allograft animal model in rats. Methods Sixteen rats were randomly allocated into 2 groups.Control group(n=8) received normal NS in vein just before the reperfusion of the graft.UTI group(n=8) received 10 000 U/kg UTI just before the reperfusion.After 2 hours of reperfusion,the recipient′s arterial blood from the donor lung′s pulmonary vein was taken and blood gases were measured.Then the animals were put to death,and a portion of grafts were taken for microscopic study.Other parts of the donor lungs were frozen in liquid nitrogen and assayed for wet/dry weight ratio,the expression of IL-8,myeloperoxidase(MPO) and ICAM-1 mRNA(measured by RT-PCR) in lung tissue. Results In UTI group,PaO_2/FiO_2 in arterial blood was significantly better [(38.62±0.75) kPa vs(31.57±1.85) kPa,P0.05)] and W/D ratio[(4.74±0.28) vs(5.00±0.12),P0.05],ICAM-1 mRNA, MPO[(0.63±0.23) vs(0.84±(0.22)),P0.05] were significantly lower than in control group.Histological appearances showed less lung tissue damage in UTI group.But the concentrations of IL-8[(173.43±27.64) vs(76.22±12.42),P0.001] in the lung tissue of the UTI group were significantly higher than their counterparts. Conclusions This study demonstrated that ulinastatin prevented lung reperfusion injury after lung transplantation in this model.