[Effects of intravenous prostaglandin E1 on bronchial histamine reactivity].

The effects of infusion of different doses of prostaglandin E1 (12.5, 25, 50 ng kg-1 min-1) on airway responsiveness to inhaled histamine dichloride were observed in 16 subjects with normal and high bronchial reactivity. Subjects were randomized to receive PGE1 or placebo within an interval of three days. Normal saline was infused on one day and PGE1 on the other days. 10 minutes after starting the PGE1 infusion bronchial provocation was induced by histamine aerosol challenge. The provocation concentration of histaminedihydrochloride causing a 50% increase in bronchial resistance increased from 0.36 +/- 0.12 to 0.57 +/- 0.19 mg/ml in hyperreactive subjects (n.s.) and from 0.77 +/- 0.12 to 1.57 +/- 0.19 mg/ml in normal subjects (beta less than 0.05) after administration of 50 ng kg-1 min-1 PGE1 (p less than 0.05). Partial flow rates measured at maximal bronchoconstriction increased dose-dependently during the infusion of PGE1 (p less than 0.05). We conclude that intravenous administration of PGE1 partially protects against histamine-induced bronchoconstriction. In hyperreactive subjects PGE1 selectively increases flow at low lung volumes indicating an action on peripheral bronchial resistance.