noun, plural: prostacyclins
Any member from the subfamily of eicosanoids, with a chemical formula of C20H32O5, produced chiefly by mast cells and endothelium, and functions primarily as vasodilator and as an inhibitor of platelet aggregation
Eicosanoid is the generic term to refer to the compounds derived from arachidonic acid or other polyunsaturated fatty acids of 20-carbon length. Some of the prominent eicosanoids include (1) eoxins, (2) leukotrienes, (3) lipoxins, (4) prostacyclin, (5) prostaglandins, (6) resolvins, and (7) thromboxanes.
Prostacyclin is an eicosanoid with a chemical formula of C20H32O5. The major functions of prostacyclins are to act as a vasodilator and to inhibit platelet aggregation. It, therefore, increases vascular permeability. It is produced chiefly by mast cells and endothelium. The release is enhanced by bradykinin.
Prostacyclins act as a signaling molecule and employ paracrine signaling. They bind to the prostacyclin receptors (such as G protein-coupled receptors) on the cell surface of platelets and endothelial cells. This leads to cAMP production in the cytosol.
Prostacyclins, together with prostaglandins and thromboxanes, comprise the prostanoids. Prostanoids are a sub-group of eicosanoids derived from prostaglandin H compound (pentose ring). Prostacyclin is derived from prostaglandin H2 (PGH2), in particular. PGH2, in turn, is formed from the conversion of arachidonic acid through the enzyme, PGH2 synthase. Through the action of enzyme, prostacyclin synthase, PGH2) is converted into a prostacyclin.
Prostacyclins may also be produced synthetically for their therapeutic use. Synthetic prostacyclin analogues are administered by inhalation, IV, or subcutatneously. They are used as vasodilating agent, such as in pulmonary arterial hypertension.
- prostaglandin I2 (PGI2)