Alterations In Bronchoalveolar Lavage And Plasma Endothelin-1 Levels Early After Lung Transplantation

A temporary increase in pulmonary vascular resistance is observed during the first 24 hr following lung allotransplantation. We hypothesized that such early vascular changes are secondary to endothelial injury by ischemia-reperfusion, and that this may be mediated by an increased pulmonary endothelin-1 production/release. To test this hypothesis, radioimmunoassay was used to analyze endothelin-1 levels in bronchoalveolar lavage and plasma taken before surgery and at 1 hr, 4 hr, 24 hr, and 1 week after transplantation. The study was carried out on 2 groups of mongrel dogs. One group was subjected to left single-lung allotransplantation and the other to autotransplantation. Endothelin-1 levels in the bronchoalveolar lavage samples from the lung allografts were significantly increased at 1 (0.70±0.18 pg/ml) and 4 (1.84±0.65 pg/ml) hr after transplantation compared with the preoperative value (0.14±0.05 pg/ml), and declined at 24 (0.85±0.84 pg/ml) hr after transplantation. Similarly, plasma endothelin-1 levels in the allografts were significantly increased at 1 (2.0±0.80 pg/ml) and 4 (2.0±0.71 pg/ml) hr after transplant when compared with preoperative levels (0.54±0.09 pg/ml). Plasma endothelin-1 levels, however, remained significantly high after 24 hr (1.4±0.4 pg/ml;P<0.007) and decreased after 1 week after transplant (0.89±0.32 pg/ml). On the other hand, endothelin-1 levels in bronchoalveolar lavage from the autograft group remained relatively unchanged; however, plasma levels showed a significant increase at 4 hr (6.6±1.8 pg/ml) after transplantation compared with preoperative levels (2.8±0.38 pg/ml). Elevation of endothelin-1 levels early after lung transplantation may play an important role in early high pulmonary vascular resistance and temporary graft dysfunction