The different effect of salbutamol and aminophylline on platelet activating factor-induced plasma exudation into guinea pig tracheal wall and lumen

We examined the effects of salbutamol, aminophylline and verapamil on plasma exudation into airway wall and lumen in guinea pig trachea isolated in situ. Platelet-activating factor (PAF) (50 ng/kg) induced plasma exudation into both the tissue and lumen. Aminophylline (25 mg/kg) eliminated PAF-induced plasma leakage in the tissue and lumen. Verapamil (500 μg/kg) had neither effect. Salbutamol (160 μg/kg) significantly reduced PAF-induced plasma exudation in the tissue and enhanced plasma recovery in the airway lumen. We conclude that aminophylline inhibited microvascular leakage whereas salbutamol facilitates exudated plasma across epithelium and reduced its accumulation in the tissue.