Prostaglandin

Prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids[1] that have diverse hormone-like effects in animals.

They act as autocrine or paracrine factors with their target cells present in the immediate vicinity of the site of their secretion.

Prostaglandins differ from endocrine hormones in that they are not produced at a specific site but in many places throughout the human body.

They are synthesized in the walls of blood vessels and serve the physiological function of preventing needless clot formation, as well as regulating the contraction of smooth muscle tissue.

[6][7][8] Prostaglandins were believed to be part of the prostatic secretions, and eventually were discovered to be produced by the seminal vesicles.

The biochemists Sune K. Bergström, Bengt I. Samuelsson and John R. Vane jointly received the 1982 Nobel Prize in Physiology or Medicine for their research on prostaglandins.

They are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells.

[citation needed] Prostaglandins were originally believed to leave the cells via passive diffusion because of their high lipophilicity.

The classic dogma is as follows: However, while COX-1 and COX-2 are both located in the blood vessels, stomach and the kidneys, prostaglandin levels are increased by COX-2 in scenarios of inflammation and growth.

It involves a Diels–Alder reaction which establishes the relative stereochemistry of three contiguous stereocenters on the prostaglandin cyclopentane core.