Failure of ambroxol to influence the allergen induced bronchial constriction in sensitized guinea pigs.

The action of ambroxol was tested in an in vivo guinea pig asthma model. Ambroxol, a compound with antiallergic properties effects the mediator releasing cells in vitro and surfactant secretion from alveolar type II cells. This paper deals with the action of ambroxol in an in vivo asthma model in guinea pigs. Ovalbumin sensitized guinea pigs were artificially ventilated by negative chest wall pressure, using a tank respirator. Breathing parameters were measured pneumotachographically. The experimental animals were treated with 50 mg/kg ambroxol i.p. for 5 days; control animals received saline only. The results indicate that pretreatment with ambroxol had no significant effect on the allergic bronchial constriction, while in vitro ambroxol effects on mediator releasing cells and surfactant production point to antiallergic properties. An explanation of the failure of allergenic preventing effects of ambroxol in vivo may be its insufficient concentration in the tissue.