We have studied the effects of intravenous epinephrine, albuterol, verapamil, and aminophylline on airway microvascular leakage in guinea pigs. Microvascular leakage was induced by platelet-activating factor (PAF; 50 ng/kg intravenously), which acts directly on venular endothelial cells, and measured by quantifying extravasation of Evans blue (EB) dye. Epinephrine (20 μg/kg) inhibited PAF-induced changes in dye leakage in larynx and main bronchi; at 80 and 160 μg/kg, significant inhibition was observed in all airways studied. This effect was reversed by phentolamine (2.5 mg/kg) or prazosin (100 μg/kg). By contrast, albuterol (20 to 320 μg/kg) and aminophylline (12.5 to 50 mg/kg) failed to inhibit dye leakage at any dose studied. Verapamil inhibited PAF-increased leakage in larynx, main bronchi, and intrapulmonary airways at the lowest dose tested (125 μg/kg), although inhibition was not dose dependent. These results suggest that the antiedema effect of epinephrine may be due to vasocon...
Effect of anti-asthma drugs on microvascular leakage in guinea-pig airways
BOSCHETTO, Piera;
1989
Abstract
We have studied the effects of intravenous epinephrine, albuterol, verapamil, and aminophylline on airway microvascular leakage in guinea pigs. Microvascular leakage was induced by platelet-activating factor (PAF; 50 ng/kg intravenously), which acts directly on venular endothelial cells, and measured by quantifying extravasation of Evans blue (EB) dye. Epinephrine (20 μg/kg) inhibited PAF-induced changes in dye leakage in larynx and main bronchi; at 80 and 160 μg/kg, significant inhibition was observed in all airways studied. This effect was reversed by phentolamine (2.5 mg/kg) or prazosin (100 μg/kg). By contrast, albuterol (20 to 320 μg/kg) and aminophylline (12.5 to 50 mg/kg) failed to inhibit dye leakage at any dose studied. Verapamil inhibited PAF-increased leakage in larynx, main bronchi, and intrapulmonary airways at the lowest dose tested (125 μg/kg), although inhibition was not dose dependent. These results suggest that the antiedema effect of epinephrine may be due to vasocon...I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
