There is evidence to suggest that prostaglandins participate in the mediation of the inflammatory response. In several tissues, the production of inflammation has been associated with the release of prostaglandin. The inhibitory effect of some anti-inflammatory agents on prostaglandin synthesis further suggests a prostaglandin role in inflammation. Prostaglandins may also play a role in the pathogenesis and treatment of asthma. The E prostaglandins are potent bronchodilators, whereas the F compounds are bronchoconstrictors. In addition, PGE2 prevents bronchoconstriction induced by agents such as histamine, serotonin, bradykinin, and acetylcholine. There is evidence to suggest that in addition to their effects on bronchial smooth muscle, prostaglandins may also have an antiallergic activity that may prove useful in the treatment of asthma.