Azelastine inhibits bronchial hyperreactivity to acetylcholine in guinea pigs

Abstract

Contractile responses to acetylcholine were measured using isolated tracheae obtained from actively sensitized guinea pigs 0.5, 1, 5, 20, 24, 48 and 72 h after antigen challenge. Tracheal contractions to acetylcholine and to histamine were significantly increased 20 h but not 0.5, 1, 5, 24, 48 and 72 h after antigen challenge indicating bronchial hyperreactivity. When animals were pretreated with azelastine and then exposed to antigen challenge, concentration-response curve to acetylcholine did not differ from that obtained in control (non-challenged) tracheae. It is likely that azelastine is able to inhibit bronchial hyperresponsiveness to chemical mediators of bronchial asthma.

Inhibition of Allergic and Nonallergic Leukotriene C₄ Formation and Histamine Secretion by Azelastine: Implication for Its Mechanism of Action

“…The ability of azelastine to inhibit the synthesis of LTC4 [this study], its LT antagonism [15] and its inhibition of antigen-induced increased capillary permeability [9,18] may explain its mucus viscosity-lowering activ ity in late phase asthm a in guinea pigs [8].…”

“…It exerts anti inflam m atory activity, i.e., it inhibited an antigen-in duced increase in capillary perm eability in experi mental anim al model systems [9,18]. It lowers the viscosity of mucus associated with the late phase asthm atic responses in guinea pigs [8].…”

The effect of azelastine on an acute non-specific inflammation in comparison to the effect of dexamethasone

“…In the present paper the influence of azelastine was investigated on the inflammatory process in this model. Azelastine is a novel antiallergic agent with an inhibitory effect on the early and late phase asthmatic reaction [2]. Its antiallergic properties may stem not only from antagonizing the histamine-induced effects but also from a capacity to inhibit the release of histamine and other allergic mediators from mast cells [for instance 3].…”