Biochemistry and physiology of the leukotrienes.

Based on the studies that have used human subjects and materials, and a much larger body of data from animal and in vitro experiments, one can conclude that the LTs are potent bronchoconstrictors in normal and asthmatic subjects. A major part of their action is mediated directly via the cysLT-1 receptor on airway smooth muscle. There is also evidence for an effect on airway hyperresponsiveness probably via eosinophil recruitment and activation, airway edema, and possibly airway nerves. Taken together, these studies support a key role for the leukotrienes in asthma. However, additional studies are needed to further define their effects on the airway inflammatory response.