EDN1 and pulmonary arterial hypertension: To dissect ET-1-specific as well as ETB-specific effects on pulmonary inflammation and PAH-associated cardiovascular pathologies independent of additional inflammatory stimuli, we first investigated age-dependent effects in two transgenic mouse models of (i) prepro-ET-1 overexpression (preETtg) and (ii) rescued ETB deficiency (ETB-/-).