Inflammatory mediators, tachykinins and enkephalinase in airways

Immunologic and nonimmunologic stimuli evoke responses in the airways by complex mechanisms, often involving mast cells and mast cell-derived mediators. These mechanisms can be investigated using isolated mast cell lines for biochemical and physiologic studies. Neuropeptides as well as the enzymes that degrade neuropeptides are present in airway tissues. In the case of substance P, metabolism in the airway has demonstrated physiologic significance. The physiologic response to a stimulus depends upon the interaction between locally released inflammatory mediators and neuropeptides and the enzymes which degrade them.