ALTERATIONS IN BRONCHOALVEOLAR LAVAGE AND PLASMA ENDOTHELIN-1 LEVELS EARLY AFTER LUNG TRANSPLANTATION

A temporary increase in pulmonary vascular resistance is observed duri ng 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, r adioimmunoassay was used to analyze endothelin-1 levels in bronchoalve olar 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 group s of mongrel dogs. One group was subjected to left single-lung allotra nsplantation and the other to autotransplantation, Endothelin-1 levels in the bronchoalveolar lavage samples from the lung allografts were s ignificantly 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 (0.1 4+/-0.05 pg/ml), and declined at 24 (0.85+/-0.84 pg/ml) hr after trans plantation. Similarly, plasma endothelin-1 levels in the allografts we re significantly increased at 1 (2.0+/-0.80 pg/ml) and 4 (2.0+/-0.71 p g/ml) hr after transplant when compared with preoperative levels (0.54 +/-0.09 pg/ml). Plasma endothelin-1 levels, however, remained signific antly 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, endoth elin-1 levels in bronchoalveolar lavage from the autograft group remai ned 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 lev els early after lung transplantation may play an important role in ear ly high pulmonary vascular resistance and temporary graft dysfunction.