In male Sprague-Dawley rats, oral administration of rodatristat ethyl at doses of 100 or 200 mg/kg once daily for 28 days results in a dose-dependent decrease in serum, gut, and lung 5-HT levels. This treatment significantly reduces pulmonary arterial pressure as well as pulmonary vessel wall thickness and occlusion in rats with monocrotaline (MCT)-induced pulmonary hypertension[2].