The aim of this study was to investigate whether or not endothelin-1 content of bronchoalveolar lavage was elevated in allografted lungs during acute rejection.

After single lung allotransplantation, dogs were immunosuppressed with triple standard therapy and divided into 2 groups. Group 1(Immunosupression ; n=4) was maintained on immunosuppression as controls. In group 2(Rejectin ; n=13), triple therapy was discontinued to induce acute rejection from postoperative day 5.

At postoperative day 9, broncholaveolar lavage was done through bronchoscopy in native unoperated lung and transplanted lung in group 1. Bronchoalveolar lavage was repeated in group 2 in the same way. Endothelin-1 content of bronchoalveolar lavage was measured by radiommunoassay.

Endothelin-1 content in transplanted lung of group 2 was compared to that of transplanted lung of group 1 and to that of native unoperated lung of group 2.

Endothelin-1 content of bronchoalveolar lavage in transplanted lung of group 2 was comparable to that of group 1(42.18±26.39 vs 3.08±3.08pg/ml ; p=0.08). Endothelin-1 content of bronchoalveolar lavage in transplanted lung of group 2 was comparable to that of native unoperated lung of group 2(42.18±26.39 vs 3.74±2.62pg/ml ; p=0.07).

Endothelin-1 content of bronchoalveolar lavage in transplanted lung was altered during acute rejection, but without statistical significance.