Cyclooxygenase is the major producer of prostacyclin. Prostacyclin binding to its receptor increases vasodilation and decreases platelet aggregation. The receptor is a G-protein coupled receptor, upon its binding it activates G proteins causing the activation of adenylyl cyclase and production of cAMP messenger molecules. cAMP activates PKA (protein kinase A) which phosphorylates downstream effectors that lead to a specific cellular response.In vasodilation, the PKA activity causes phosphorylation of MLCK, decreasing its activity, resulting in dephosphorylation of MLC of myosin. This leads to smooth muscle relaxation resulting in vasodilation.

Intracellular Signalling Through Prostacyclin Receptor and Prostacyclin References