EDN1 and acute respiratory distress syndrome: Increased levels of endothelin-1 (ET-1), a potent vasoconstriction agent (Davenport and Maguire, 1994), have been reported clinically in ARDS patients where they contribute not only to pulmonary vasoconstriction but also to promote lung edema (Druml et al., 1993; Sanai et al., 1996; Nakano et al., 2007).