Leukotriene Synthesis

Arachidonic acid is converted to a variety of linear hydroperoxy (–OOH) acids by a separate pathway involving a family of lipoxygenases (LOX).
For example, 5-LOX converts arachidonic acid to 5-hydroperoxy-6,8,11,14 eicosatetraenoic acid ([5-HPETE]; Fig. 1). 5-HPETE is converted to a series of LT containing four double bonds, the nature of the final products varying according to the tissue. LT are mediators of allergic response and inflammation. Inhibitors of 5-LOX and LT-receptor antagonists are used in the treatment of asthma. [Note: LT synthesis is inhibited by cortisol and not by NSAID. Aspirin-exacerbated respiratory disease is a response to LT overproduction with NSAID use in ~10% of individuals with asthma.]

Figure 1:  Overview of the biosynthesis and function of some important prostaglandins (PG), leukotrienes (LT), and a thromboxane (TX) from arachidonic acid. [Note: The arachidonic acid in the membrane phospholipid was derived from the ω-6 essential fatty acid (FA), linoleic, also an ω-6 FA.] PI = phosphatidylinositol; NSAID = nonsteroidal anti-inflammatory drugs; Glu = glutamate; Cys = cysteine; Gly = glycine.

مواضيع ذات صلة

آلية عمل المجموعة الأولى من الهرمونات

الهرمونات وآليات الاستتباب

تدرك (تقويض) الهرمونات وتعطيلها

نقل الهرمونات في البلازما

تغاير خزن الهرمونات وإفرازها

تخليق POMC ومعالجته

The Amino Acids

Absorption & Transport of Transition Metals

Physiologic Roles of The Essential Transition Metals

تخليق الأنجيوتنسين

تخلیق PTH

تخليق الأنسولين