Effect of disodium cromoglycate on the action of bronchoactive agents in guinea-pig tracheal strips.

The effect of disodium cromoglycate (DSCG) on the action of various bronchoactive agents was investigated using isolated guinea-pig tracheal strips. DSCG attenuated the acetylcholine-induced contractile responses and shifted the dose-response curve of acetylcholine downward. It also attenuated the histamine-, serotonin-, bradykinin- and PGF2 alpha-induced contractile responses dose-dependently. On the other hand, DSCG potentiated the isoprenaline (isoproterenol)-, epinephrine-, PGE2- and salbutamol-induced relaxation responses, and shifted these dose-response curves downward. Such a shift became dominant by increasing the dose of DSCG. The above results suggest that DSCG might have a direct action on bronchial smooth muscle in addition to the inhibition of the release of chemical mediators from mast cells.