Rolipram inhibits airway microvascular leakage induced by platelet-activating factor,histamine and bradykinin in guinea-pigs

Abstract— Rolipram (0·1–1000 μg kg^?1, i.v.) reduced the increase in microvascular permeability induced by platelet-activating factor (PAF; 50 ng kg^?1, i.v.) at different sites of the guinea-pig airways. Rolipram (1–100μg kg^?1, i.v.) inhibited histamine (30μg kg^?1, i.v.)-and bradykinin (0·3 μg kg, i.v.)-induced airway microvascular leakage. These effects of rolipram were obtained at doses which inhibit histamine (7–20 μg kg^?1 min^?1)-induced bronchoconstriction (IC50 = 3 ± 1 μg kg, i.v.) without depressing arterial blood pressure in the guinea-pig. Aminophylline (50 mg kg^?1) did not change the effect of PAF. The anti-exudative effect of rolipram is of potential therapeutic value in asthma.