ABSTRACT
Investigations into the effect of slow-reacting substance of anaphylaxis (SRS-A) in animal models indicate that it is an important allergic mediator with potent activity as a contractor of bronchial smooth muscle (1). Following the elucidation of the structure of SRS-A as leukotrienes (LTs) in 1979 (2), the total chemical synthesis of leukotrienes (3) was described, enabling pharmacologists to study the effect of pure LTs in animal models in vitro and in vivo (4,5). When sufficient quantities of pure LTs became available, studies of the effects of LTs in humans were performed. The majority of these studies have been performed using inhaled cysteinyl leukotrienes, and a more limited number of studies have been performed with systemically administered leukotrienes and LTB4. Studies of the biological properties of leukotrienes in humans have added significantly to our understanding of the pathophysiological role of leukotrienes in disease and have helped in the evaluation of LTD4 receptor antagonists.
