PLASMA ENDOTHELIN-1 LEVELS IN HUMAN LUNG-TRANSPLANT RECIPIENTS

Endothelin-1 (ET-1) is a potent vasoconstrictor tor peptide produced b y vascular endothelial cells and is believed to play an important role in the pathophysiology of the pulmonary vasculature. We have investig ated the early changes in ET-1 plasma levels in lung transplant recipi ents at various intervals before and after isolated lung transplantati on. The mean plasma ET-1 level immediately before transplantation was 0.8 +/- 0.1 pg/ml. This was significantly increased to 2.6 +/- 0.5 pg/ ml shortly after unclamping and vascular reperfusion of the allograft, and remained high 4 h (2.3 +/- 0.5 pg/ml), 6 h (2.4 +/- 0.6 pg/ml), a nd 12 h (1.7 +/- 0.3 pg/ml) after transplantation. Thereafter, the lev el of ET-1 started to decline, reaching 1.3 +/- 0.3 pg/ml 24 h and 0.9 +/- 0.3 pg/ml 1 week after transplantation. This early increase in ET -1 plasma level is consistent with our observation of alterations in p ulmonary vascular resistance, pulmonary artery pressure and cardiac ou tput early after transplantation. These findings demonstrate that an i ncrease in plasma ET-1 levels shortly after lung transplantation may h ave a detrimental effect during the postoperative course early after t ransplantation.