ANTIGEN STIMULATION OF HUMAN PULMONARY SMOOTH-MUSCLE - AN IN-VITRO MODEL OF INFLAMMATION

Human airways in vitro contract when stimulated by anti-IgE, whereas h uman pulmonary vessels relax. Leukotriene D-4 (LTD(4)) induced a contr actile response in the airways, while in pulmonary vessels both contra ctions and relaxations were observed. The LTD(4) contractions in airwa ys were blocked by cysLT(1) receptor antagonists (MK 571, ICI 198615, and BAY x7195). In contrast none of the compounds affected the LTD(4) contractions of pulmonary veins. These results suggest that the leukot rienes which are released during antigen challenge of airways and pulm onary vessels may be acting at distinct receptors in the human lung.