Prostaglandin

Prostaglandins are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derived enzymatically from the fatty acid arachidonic acid.

History

Prostaglandins were first discovered in the 1930s by Swedish physiologist Ulf von Euler. He isolated an active substance from human semen and named it "prostaglandin" because he believed it was part of the prostatic secretions. Later research showed that prostaglandins are produced by many tissues in the body.

Structure and Synthesis

Pathway of eicosanoid synthesis

Prostaglandins are synthesized from arachidonic acid by the action of the enzyme cyclooxygenase (COX). There are two main isoforms of this enzyme: COX-1 and COX-2. The synthesis of prostaglandins involves the conversion of arachidonic acid to prostaglandin H2 (PGH2), which is then converted to various other prostaglandins by specific synthase enzymes.

Types of Prostaglandins

There are several types of prostaglandins, each with different functions:

• Prostaglandin E1 (PGE1): Known for its vasodilatory properties and ability to inhibit platelet aggregation.
• Prostaglandin E2 (PGE2): Involved in inflammation and fever regulation.
• Prostaglandin F2α (PGF2α): Plays a role in the contraction of the uterus and is used to induce labor.
• Prostacyclin (PGI2): Inhibits platelet activation and is a potent vasodilator.

Structure of Prostacyclin

Biological Functions

Prostaglandins have a wide range of biological functions, including:

• Regulation of inflammation and immune response
• Modulation of blood flow and blood clotting
• Induction of labor and control of reproductive processes
• Regulation of gastric acid secretion and protection of the gastrointestinal tract

Clinical Significance

Prostaglandins are involved in many physiological and pathological processes. They are targets for nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin, which inhibit the COX enzymes and reduce the production of prostaglandins, thereby alleviating pain and inflammation.

Related Pages

• Eicosanoid
• Cyclooxygenase
• Arachidonic acid
• Nonsteroidal anti-inflammatory drug