Prostaglandin , biological functions

Figure 8.9 Prostaglandins and leukotrienes are potent eicosanoid lipid mediators, derived from phospholipase-released arachidonic acids, that are involved in numerous homeostatic biological functions and inflammation. They are generated by cyclooxygenase isozymes and 5-lipoxygenase, respectively, and their biosynthesis and pharmacological actions are inhibited by clinically relevant nonsteroidal anti-inflammatory drugs.

How does aspirin relieve pain and reduce inflammation Aspirin blocks the synthesis of prostaglandins, 20-carbon fatty acids with a five-membered ring that are responsible for pain, inflammation, and a wide variety of other biological functions. PGF2 , the chapter-opening molecule, contains the typical carbon skeleton of a prostaglandin. 

In this chapter we will study the chemistry of lipids with a wide variety of structures and biological functions. Among these are the triglycerides that stock our adipose tissue, pain-producing prostaglandins, and steroids that determine our secondary sexual characteristics. 

A transesterification reaction that blocks prostaglandin synthesis is responsible for aspirin s activity as an anti-inflammatory agent. Prostaglandins have several different biological functions, one of which is to stimulate... 

Inceoglu B, Schmelzer KR, Morisseau C, Jinks SL, Hammock BD (2007) Soluble epoxide hydrolase inhibition reveals novel biological functions of epoxyeicosatrienoic acids (EETs). Prostaglandins Other Lipid Medial 82 42-49... 

One of the key functional roles of PUFA is as precursors to eicosanoids. Eicosanoids are a family of bioactive mediators that are oxygenated derivatives of the 20-carbon PUFA dihomo-y-linolenic, arachidonic and eicosapentaenoic acids. Eicosanoids include prostaglandins (PG) and thromboxanes (TX), which together are termed prostanoids, and leukotrienes (LT), lipoxins (LX), hydroperoxyeicosatetraenoic acids (HPETE) and hydroxyeicosatetraenoic acids (HETE). In most conditions the principal precursor for these compounds is arachidonic acid, and the eicosanoids produced from arachidonic acid sometimes have more potent biological functions than those released from dihomo-y-linolenic or eicosapentaenoic acids. The precursor PUFA is released from membrane diacylglycerophospholipids by the action of phospholipase A or from membrane phosphatidylinositol-4,5-bisphosphate by the actions of phospholipase C and a diacylglycerol (DAG) lipase (Figure 7). 

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