• Asthma
• Allergic lung disease
• COPD ÀÜ Mechanisms
• COPD Pharmacology
• Asthma Pharmacology

Prostanoids are important endogenous signalling molecules that are produced locally both physiologically and in inflammatory diseases and have potent effects on a number of inflammatory processes. Endogenous prostaglandin production consists of several stages: conversion of membrane phospholipid to arachidonic acid via phospholipase A2, conversion of arachidonic acid to PGG₂ by cyclo-oxygenase (COX), a peroxidase reaction to produce PGH₂ and then conversion of PGH₂ by specific synthases and isomerases to PGE₂, PGI₂, PGF_2α or PGD₂. COX is present in most cells, and it is the synthase/isomerase complement of the cell that determines the balance of prostanoids produced by a given cell type. Inflammatory cells tend to produce PGD₂ and PGF_2α, whereas airway structural cells such as smooth muscle (airway and vascular), fibroblasts, endothelial and epithelial cells produce an abundance of PGE₂ or PGI₂.1

In contrast to PGD₂ and PGF_2α, which are predominantly pro-inflammatory, PGE₂ is predominantly anti-inflammatory.2 PGE₂ inhibits acetylcholine release from parasympathetic nerve endings, mast cell mediator release and cellular responses in eosinophils, macrophages …