Leukotrienes and their possible significance for the pathogenesis of asthma

Six years ago the structure of slow reacting substance of anaphylaxis (SRS-A), a strongly bronchoconstrictive substance, has been unravelled SRS-A proved to be a mixture of different closely related compounds, now denominated as sulfidopeptide Leukotrienes. Leukotrienes possess a conjugated triene system and one or more oxygen functions. They are formed from membrane derived arachidonic acid by an initial oxygenation by the enzyme lipoxygenase. Sofar the following leukotrienes have been characterized leukotriene A4, B4, C4, D4, E4 and F4. Leukotrienes possess important biological properties. Leukotriene B4 is strongly chemotactic for leukocytes, whereas the sulfidopeptide leukotrienes C4, D4 and E4 are strongly spasmogenic. In this review the formation and the different biological activities of leukotrienes and the possible role of leukotrienes in the asthmatic process will be discussed.