Prostacyclin synthesis pathway (PGI2 pathway)

The prostacyclin synthesis pathway is a critical biochemical route responsible for the production and signaling of prostacyclin (PGI2), a potent vasodilator and inhibitor of platelet aggregation (Source: StatPearls, "Prostacyclin"). The pathway begins with the release of arachidonic acid from the cell membrane, which is converted into prostaglandin H2 (PGH2) by cyclooxygenase (COX) enzymes, and subsequently into PGI2 by the enzyme prostacyclin synthase (PTGIS) (Source: UniProt, P24557). PGI2 then acts as a ligand for the prostacyclin receptor (IP receptor), a G protein-coupled receptor that, upon activation, increases intracellular cyclic AMP (cAMP) levels (Source: UniProt, P43119). This increase in cAMP leads to the relaxation of vascular smooth muscle cells and prevents the activation and aggregation of platelets (Source: PubMed, PMID: 25583631). In clinical medicine, this pathway is a primary target for treating pulmonary arterial hypertension (PAH), a condition characterized by a deficiency in endogenous prostacyclin production (Source: NIH, "Pulmonary Arterial Hypertension"). Pharmacological interventions include the administration of synthetic prostacyclin analogs or selective IP receptor agonists to compensate for this deficiency and improve hemodynamic function (Source: PubMed, PMID: 30234148).

Other names

PGI2 synthesis pathwayProstacyclin-IP receptor axisProstacyclin signaling pathwayEicosanoid pathway (prostacyclin branch)

Agonism of the prostacyclin receptor (IP receptor) to increase intracellular cAMP levels, leading to vasodilation and inhibition of platelet aggregation; supplementation of exogenous prostacyclin analogs to mimic endogenous PGI2 activity.