Biophysiology of the Prostaglandins and its Receptors

Prostaglandins are derivatives of prostanoic acid and they are 20-carbon fatty acids with a cyclopentane ring at C-8 to C-12. They are produced by all nucleated cells except lymphocytes. They are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells. Prostaglandins are potent but have a short half-life before being inactivated and excreted. Therefore, they send only paracrine (locally active) or autocrine (acting on the same cell from which it is synthesized) signals. Although they are technically hormones, they are rarely classified as such. The prostaglandins, together with the thromboxanes and prostacyclins, form the prostanoid class of fatty acid derivatives.