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The prostaglandins are a group of hormone-like lipid compounds that are derived enzymatically from fatty acids and have important functions in the animal body. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring.

They are mediators and have a variety of strong physiological effects, such as regulating the contraction and relaxation of smooth muscle tissue.[1] Prostaglandins differ from endocrine hormones in that they are not produced at a specific site but in many places throughout the human body. They act as autocrine or paracrine factors with their target cells present in the immediate vicinity of the site of their secretion.

The prostaglandins, together with the thromboxanes and prostacyclins, form the prostanoid class of fatty acid derivatives, a subclass of eicosanoids.

The abbreviation for "prostaglandin" is PG; specific prostaglandins are named with a letter (which indicates the type of ring structure) followed by a number (which indicates the number of double bonds in the hydrocarbon structure). For example, prostaglandin E1 is abbreviated PGE1 or PGE1, and prostaglandin I2 is abbreviated PGI2 or PGI2. The number is traditionally subscripted when the context allows, but as with many similar subscript-containing nomenclatures, the subscript is simply forgone in many database fields that can store only plain text (such as PubMed bibliographic fields), and readers are used to seeing and writing it without subscript.

History and name[edit]





Biosynthesis of eicosanoids

Prostaglandins are found in most tissues and organs. They are produced by almost all nucleated cells. They are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells. They are synthesized in the cell from the essential fatty acids (EFAs).

An intermediate arachidonic acid is created from diacylglycerol via phospholipase-A2, then brought to either the cyclooxygenase pathway or the lipoxygenase pathway to form either prostaglandin and thromboxane or leukotriene respectively. The cyclooxygenase pathway produces thromboxane, prostacyclin and prostaglandin D, E and F. Alternatively, the lipoxygenase enzyme pathway is active in leukocytes and in macrophages and synthesizes leukotrienes.

Release of prostaglandins from the cell[edit]



Prostaglandins are produced following the sequential oxidation of arachidonic acid, DGLA or EPA by cyclooxygenases (COX-1 and COX-2) and terminal prostaglandin synthases. The classic dogma is as follows:

  • COX-2 produces prostaglandins through stimulation.


Prostaglandin E synthase[edit]


Other terminal prostaglandin synthases[edit]

Terminal prostaglandin synthases have been identified that are responsible for the formation of other prostaglandins. For example, hematopoietic and lipocalin prostaglandin D synthases (hPGDS and lPGDS) are responsible for the formation of PGD2 from PGH2. Similarly, prostacyclin (PGI2) synthase (PGIS) converts PGH2 into PGI2. A thromboxane synthase (TxAS) has also been identified. Prostaglandin-F synthase (PGFS) catalyzes the formation of 9α,11β-PGF2α,β from PGD2 and PGF from PGH2 in the presence of NADPH. This enzyme has recently been crystallized in complex with PGD2[5] and bimatoprost[6] (a synthetic analogue of PGF).



The diversity of receptors means that prostaglandins act on an array of cells and have a wide variety of effects such as:



The following is a comparison of different types of prostaglandin, prostacyclin I2 (PGI2), prostaglandin E2 (PGE2), and prostaglandin F (PGF).

Type Receptor Receptor type Function
EP2 Gs
EP3 Gi

Role in pharmacology[edit]


Examples of prostaglandin antagonists are:

Clinical uses[edit]

Synthetic prostaglandins are used:


  1. ^ Nelson, Randy F. (2005). An introduction to behavioral endocrinology (3rd ed.). Sunderland, Mass: Sinauer Associates. p. 100. ISBN 0-87893-617-3. 
  3. ^ Goldblatt MW (May 1935). "Properties of human seminal plasma". J Physiol 84 (2): 208–18. PMC 1394818. PMID 16994667. 
  5. ^ Komoto J, Yamada T, Watanabe K, Takusagawa F (2004). "Crystal structure of human Prostaglandin-F synthase (AKR1C3)". Biochemistry 43 (8): 2188–98. doi:10.1021/bi036046x. PMID 14979715. 
  6. ^ Komoto J, Yamada T, Watanabe K, Woodward D, Takusagawa F (2006). "Prostaglandin F2alpha formation from prostaglandin H2 by Prostaglandin-F synthase (PGFS): crystal structure of PGFS containing bimatoprost". Biochemistry 45 (7): 1987–96. doi:10.1021/bi051861t. PMID 16475787. 
  7. ^ a b Rang, H. P. (2003). Pharmacology (5th ed.). Edinburgh: Churchill Livingstone. p. 234. ISBN 0-443-07145-4. 
  10. ^ Medscape Early Penile Rehabilitation Helps Reduce Later Intractable ED
  11. ^ LaBonde, MS, DVM, Jerry. "Avian Reproductive and Pediatric Disorders" (PDF). Michigan Veterinary Medical Association. Archived from the original on 2008-02-27. Retrieved 2008-01-26. 

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