Bronchopulmonary responses to prostaglandin F2alpha, histamine and acetylcholine in the dog

Abstract

This investigation compared quantitatively the effects of prostaglandin F2alpha, histamine and acetylcholine on pulmonary airway resistance and dynamic lung compliance in the spontaneously breathing, anesthetized dog. Airway responses were evaluated by computer analysis before and after pharmacological blockade by either atropine or propranolol. In a dose range of 1.0-10.0 mug/kg i.v., prostaglandin F2alpha was the most potent bronchoconstrictor studied. At the highest dose, prostaglandin F2alpha increased airway resistance 153.3% and decreased lung compliance 55.4% from basal levels. Similar doses of either histamine or acetylcholine produced much less effect. Atropine significantly reduced the bronchopulmonary responses evoked by histamine, acetylcholine and prostaglandin F2alpha. Propranolol did not inhibit any of the respiratory effects of those bronchoconstrictors analyzed. The bronchopulmonary effects of prostaglandin F2alpha and histamine appear to be augmented by cholinergic stimuli.