Eicosanoids (from the Greek eicosa, "twenty") are a large family of inter- and intracellular signaling molecules derived from arachidonic acid, a fourfold unsaturated C20 fatty acid sequestered in membrane phospholipids. Eicosanoid production is tightly controlled by mediators of membrane lipid mobilization, and by the cellular concentrations and activities of the enzymes involved in their metabolism. Eicosanoids are capable of mediating a great variety of cellular functions, including processes as seemingly diverse as vascular contractility, inflammatory response, protection of the gastric mucosa, and renal function. Eicosanoids are rapid responders to external stimuli, and in keeping with this role, they are not stored within the cell, but are rapidly synthesized and then quickly degraded as a result of spontaneous hydrolysis or enzyme-mediated inactivation.
The first eicosanoids identified were members of a category known as prostaglandins. Prostaglandins were discovered in the 1930s when a reproductive physiologist, von Euler, observed that a substance in human semen induced contraction of uterine smooth muscle. Because he assumed that the active agent was produced by the prostate gland, he named this substance "prostaglandin." Members of the leukotriene family were first identified in the early 1940s as a result of their effects as mediators of anaphylaxis. In 1969, Piper and Vane showed that aspirin inhibited vasoactive substances produced by rabbit aorta, and in 1971, Vane discovered that prostaglandins were the target of nonsteroidal anti-inflammatory drug (NSAID) activity. Samuelsson identified thromboxanes as distinct products in 1979. In the latter half of the 20th century, the recognition of eicosanoids as important mediators of both normal and pathologic physiological responses has added a wealth of data to this increasingly complex field.
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Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.