IP receptor (prostacyclin pathway)

Class

Prostacyclin pathway agonist

The IP receptor is a G protein–coupled receptor found mainly on vascular smooth muscle cells and platelets. Its natural ligand, prostacyclin (prostaglandin I2), is produced by the endothelium lining blood vessels and acts locally to relax smooth muscle, widen blood vessels, and reduce platelet clumping. In pulmonary arterial hypertension, the vessels supplying the lungs undergo abnormal narrowing and remodeling, and endogenous prostacyclin signaling is often reduced. Restoring this signaling through IP receptor agonism lowers vascular resistance, improves blood flow through the lungs, and may slow the vessel-wall changes that drive disease progression. Because natural prostacyclin degrades within minutes in the bloodstream, therapeutic strategies rely either on stable synthetic analogs of the molecule or on small molecules designed to bind the receptor directly with a longer duration of action. These agents can be delivered intravenously, by inhalation, or orally, with the route influencing how much drug reaches the lungs versus the rest of the circulation. This mechanism broadly matters in pulmonary hypertension and related vascular disorders where insufficient vasodilatory signaling contributes to elevated pressure and impaired blood flow.