Abstract
We devised a new method for measuring responses of canine airway musculature, bronchosecretion and bronchial vasculature simultaneously, in situ, and investigated the effects of prostaglandins F2α and E2 and antigen-antibody reaction by using this model. The right bronchial artery was perfused with blood at a constant flow under artificial respiration. Airway musculature response was measured as a change in ventilation overflow with a modification of the Konzett-Rössler method; the airway secretory activity was measured with our stopper method for secretion volume and with the glass plate method for viscosity. Close intraarterial injections of prostaglandin (PG) F2α, 0.01-10 μg, into the right bronchial artery produced bronchomuscular and vascular constrictions, while those of PGE2, 0.01-3 μg, produced dilatation in a dose dependent manner. A close intraarterial injection of 1 mg protein of ascaris suum antigen to dogs with positive skin reaction produced bronchoconstriction and vascular dilatation. Thirty min intraarterial infusions of PGF2α, 0.3-3 μg/min, and ascaris antigen, 0.03-0.3 mg protein/min, resulted in a dose-dependent increase in the volume of airway secretions, while those of PGE2, 0.1-1.0 μg/min, did not alter the secretory activity. These findings indicate that prostaglandin F2α in relatively high doses increases both bronchomotor tone and bronchosecretory activity, as does antigen-antibody reaction with ascaris antigen, and that the present method is useful for evaluating effects of drugs on the respiratory tract.
