Rationale for ET Receptor Antagonism in PAH
- In patients with PAH:
- Plasma ET-1 levels are increased, and levels correlate with disease severity
- Increased ET-1 immuno-reactivity in lung vasculature (plexiform lesions)
- Blockade of ET-1 activity is expected to prevent its detrimental effects
- ET receptor antagonists are effective in animal models of pulmonary hypertension