DUAL MODES OF ACTION FOR DISODIUM CROMOGLYCATE IN INHIBITION OF ANTIGEN‐INDUCED CONTRACTIONS OF GUINEA‐PIG ISOLATED AIRWAYS SMOOTH MUSCLE

Abstract

1. Disodium cromoglycate (DSCG; 10 μmol/l‐1 mmol/l) relaxed the tone induced in the guinea‐pig isolated trachea by histamine (5 μmol/l). Both isoprenaline and fenoterol were approximately 1000 times more potent than DSCG in relaxing tracheal smooth muscle. 2. Ovalbumin (1 μg/ml) contracted isolated tracheal and parenchymal strips from sensitized guinea‐pigs. The sensitization procedure used was selective for eliciting IgG antibody production. 3. In concentrations equieffective for relaxation of the isolated trachea, fenoterol (20 nmol/l), isoprenaline (60 nmol/l) and DSCG (100 μmol/l) inhibited ovalbumin‐induced contractions of both tracheal and parenchymal strip preparations. 4. DSCG produc..