prostaglandins are known for their role in different physiological do not have any recognized role
Answers
Prostaglandin, any of a group of physiologically active substances having diverse hormonelike effects in animals. Prostaglandins were discovered in human semen in 1935 by the Swedish physiologist Ulf von Euler, who named them, thinking that they were secreted by the prostate gland. The understanding of prostaglandins grew in the 1960s and ’70s with the pioneering research of Swedish biochemists Sune K. Bergström and Bengt Ingemar Samuelsson and British biochemist Sir John Robert Vane. The threesome shared the Nobel Prize for Physiology or Medicine in 1982 for their isolation, identification, and analysis of numerous prostaglandins.
Prostaglandin
QUICK FACTS
KEY PEOPLE
Elias James Corey
Bengt Ingemar Samuelsson
Sir John Robert Vane
Sune K. Bergström
RELATED TOPICS
Hormone
Lipid
Fatty acid
NSAID
Eicosanoid
Prostanoid
Prostacyclin
Synthesis Of Prostaglandins
The prostaglandins are made up of unsaturated fatty acids that contain a cyclopentane (5-carbon) ring and are derived from the 20-carbon, straight-chain, polyunsaturated fatty acid precursor arachidonic acid.

Arachidonic acid is a key component of phospholipids, which are themselves integral components of cell membranes. In response to many different stimuli, including various hormonal, chemical, or physical agents, a chain of events is set in motion that results in prostaglandin formation and release. These stimuli, either directly or indirectly, result in the activation of an enzyme called phospholipase A2. This enzyme catalyzes the release of arachidonic acid from phospholipid molecules. Depending on the type of stimulus and the enzymes present, arachidonic acid may diverge down one of several possible pathways. One enzyme, lipoxygenase, catalyzes the conversion of arachidonic acid to one of several possible leukotrienes, which are important mediators of the inflammatory process. Another enzyme, cyclooxygenase, catalyzes the conversion of arachidonic acid to one of several possible endoperoxides. The endoperoxides undergo further modifications to form prostaglandins, prostacyclin, and thromboxanes. The thromboxanes and prostacyclin have important functions in the process of blood coagulation.
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Biological Activities Of Prostaglandins
Prostaglandins have been found in almost every tissue in humans and other animals. Plants synthesize molecules similar in structure to prostaglandins, including jasmonic acid (jasmonate), which regulates processes such as plant reproduction, fruit ripening, and flowering. Prostaglandins are very potent; for example, in humans some affect blood pressure at concentrations as low as 0.1 microgram per kilogram of body weight. The structural differences between prostaglandins account for their different biological activities. Some prostaglandins act in an autocrine fashion, stimulating reactions in the same tissue in which they are synthesized, and others act in a paracrine fashion, stimulating reactions in local tissues near where they are synthesized. In addition, a given prostaglandin may have different and even opposite effects in different tissues. The ability of the same prostaglandin to stimulate a reaction in one tissue and inhibit the same reaction in another tissue is determined by the type of receptor to which the prostaglandin binds.