摘要：

We have investigated the effect of inhaled formoterol (0.75 mg/ml, 60 breaths) and salbutamol (25 mg/ml, 60 breaths) against airway microvascular leakage and bronchoconstriction induced by inhaled platelet-activating factor (PAF) and histamine in anaesthetized guinea pigs. Lung resistance ( R L ) was measured for 6 min after challenge, followed by measurement of extravasation of Evans blue dye into airway tissues, used as an index of airway microvascular leakage. PAF (0.1, 0.4 and 1 m M ; 30 breaths) caused a significant increase in R L and extravasation of dye, but the responses were smaller than those induced by histamine (5 m M , 30 breaths). Both formoterol and salbutamol caused a small but significant inhibition of extravasation in the distal intrapulmonary airways induced by PAF (0.1 and 0.4 m M for formoterol and 0.1 m M for salbutamol), and only formoterol reduced the increase in R L induced by 1 m M PAF. These drugs also inhibited both airway effects of histamine to a higher degree. In conclusion, formoterol and salbutamol can partly inhibit airway microvascular leakage and bronchoconstriction induced by inhaled PAF and histamine. The inhibitory potency of β (in2)-adrenoceptor agonists may be dependent on the inflammatory mediator inducing the airway effects.

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