Prostaglandins

Prostaglandins and thromboxanes are eicosanoids that are derived from a common pathway (Figure 19.30), whereas the related leukotrienes are derived from arachidonic acid via a different pathway.

Structures of the major prostaglandins and thromboxane A 2 are shown in Figure 19.29. In the names of prostaglandins, such as PGF 2, PGE 2, or PGF 2, the subscripted number refers to the number of double bonds in the molecule and the / designation indicates whether the hydroxyl group at position 9 is cis to the 11-hydroxyl () or trans to the 11-hydroxyl ().

Eicosanoids (like prostaglandin) exert specific physiological effects on target cells, like hormones. However, eicosanoids are distinct from most hormones in that they cat locally, near their sites of synthesis, and they are catabolized extremely rapidly. Thus, eicosanoids are considered to be locally acting hormones.

Common prostaglandins include PGA, PGE, PGF, PGF 2, PGH, PGH 2, PGE 2, and PGI 2.

See also: Prostaglandin Biosynthesis, NSAIDs, Eicosanoid Functions

INTERNET LINKS:

> 1. Eicosanoids

> 2. Prostaglandin and Leukotriene Metabolism

> 3. COX-2 Inhibitors