[Leukotrienes and the lung].

The implication of "slow reacting substance of Anaphylaxis" SRS-A in the pathogenesis of asthma was realised in 1950. In recent years SRS-A has been shown to be a mixture of varied composition: The Leukotrienes (LT) C4, D4 and E4. These substances derive their arachidonic acid through the 5-lipoxygenase. The LT B4, which is not conjugated to glutathione (as compared to LT C4, D4 and E4) possesses powerful chemotactic activity and an (indirect) contractile effect on smooth muscle. LTC4, D4, E4 in vitro and in vivo, both by inhalation or intravenously, are powerful bronchoconstrictors clearly superior to histamine. The effects of C4 and LTD4 predominantly affect the peripheral airways.