MAST-CELL TRYPTASE AND ASTHMA

Recent physiological and pharmacological studies have indicated the po tential importance of tryptase, the major protein component in mast ce lls, in inflammatory diseases (especially asthma), Being released at i nflammatory sites after the activation of mast cells, tryptase is capa ble of causing bronchohyperresponsiveness and infiltration of eosinoph ils, neutrophils, etc, in animal airways. The mechanisms by which tryp tase causes bronchoconstriction involve probably the potentiation of o ther chemical mediators such as histamine, production of bradykinin vi a the hydrolysis of kininogen, and cleavage of the bronchodilating pep tides VIP (vasoactive intestinal peptide) and PHM (peptide histidine-m ethionine), Tryptase has also been found to be a potent mitogen in vit ro for airway smooth muscle cells and epithelial cells, implying its r ole in the hyperplasia of the asthmatic airways. The experimental data providing evidence for the above roles of tryptase are summarized in the present review, as well as the effects of tryptase inhibition in a nimal asthma models, The potential strategies for the development of a nti-asthmatic agents based on the inhibition of tryptase are discussed .