LEUKOTRIENES AND AIRWAYS SMOOTH-MUSCLE

The understanding of cellular and molecular,mechanisms involved in the contraction of airway smooth muscle has tremendously advanced in the recent years. Among extracellular messengers that control airway smoot h muscle contraction attention has focussed on leukotrienes since seve ral strategies for pharmacological interventions in either the product ion or the effect of these substances have been developed. Two types o f receptor, CysLT and BLT, coupled to G proteins, have been identified and airway smooth muscle contraction mostly depends on CysLT(1) recep tor activation. This activation induces intracellular calcium release lending to an increase in cytoplasmic calcium concentration responsibl e for airway smooth muscle contraction. Leukotriene antagonists are no w available and their role in asthma treatment is being defined.