Leukotriene B4

Leukotriene B4 (LTB4) is a leukotriene involved in the inflammatory response. It is produced by leukocytes (white blood cells) and has a variety of biological effects, including the attraction of neutrophils to sites of inflammation.

Structure and Synthesis

LTB4 is a lipid molecule derived from arachidonic acid, a polyunsaturated fatty acid found in the phospholipids of cell membranes. The synthesis of LTB4 involves several steps, beginning with the release of arachidonic acid from the cell membrane by the enzyme phospholipase A2. This is followed by the conversion of arachidonic acid to 5-lipoxygenase, which is then converted to LTB4 by the enzyme LTB4 synthase.

Function

The primary function of LTB4 is to mediate the inflammatory response. It does this by attracting neutrophils to sites of inflammation, where they can destroy invading pathogens. LTB4 also promotes the production of pro-inflammatory cytokines and chemokines, further amplifying the inflammatory response.

In addition to its role in inflammation, LTB4 has been implicated in a variety of other biological processes, including immune response, cell proliferation, and apoptosis.

Clinical Significance

Due to its role in inflammation, LTB4 has been implicated in a variety of inflammatory diseases, including asthma, rheumatoid arthritis, and atherosclerosis. Inhibitors of LTB4 synthesis or function are therefore being investigated as potential treatments for these conditions.