[Effect of KW-4679, a novel antiallergic drug, on platelet-activating factor (PAF)-induced bronchoconstriction, airway hyperresponsiveness and pulmonary cell accumulation in guinea pigs]

Pharmacological studies on the novel antiallergic drug HQL-79: I. Antiallergic and antiasthmatic effects in various experimental models

The effects of oral administration of 4-benzhydryloxy-1-[3-(1H-tetrazol-5-yl)-propyl]piperidine (HQL-79), a newly synthesized antiallergic drug, in various experimental allergic and asthmatic models were investigated. HQL-79 markedly inhibited immediate hypersensitivity reactions such as passive cutaneous anaphylaxis in rats, antigen-induced bronchoconstriction and nasal vascular permeability in actively sensitized guinea pigs, like epinastine and ketotifen did. Airway eosinophilia in repeatedly antigen-exposed guinea pigs was suppressed by chronic administration of HQL-79 for 2 weeks. In another experiment, the antigen-induced late asthmatic response (LAR) in metyrapone-treated guinea pigs was also ameliorated by chronic treatment with HQL-79. Moreover, HQL-79 partially inhibited the toluene diisocyanate-induced delayed-type hypersensitivity (DTH) reaction in mice when administered chronically during the immunization period. The corticosteroid dexamethasone inhibited the airway inflammatory responses in guinea pigs and the DTH in mice. These results indicate that HQL-79 has potent inhibitory effects on the immediate hypersensitivity reactions, and when administered chronically, it also inhibits airway eosinophilia, LAR and DTH, similarly to corticosteroids.

Inhibitory effect of KW-4679, an anti-allergic drug, on tachykinin-mediated airway response induced by electrical vagal stimulation in guinea pigs

We examined the effect of KW-4679 ((Z)-11-[(3-dimethylamino) propylidene]-6,11-dihydro-dibenz[b,e]oxepin-2-acetic acid monohydrochloride), an anti-allergic drug, on the tachykinin-mediated airway response in guinea pigs. Electrical stimulation of the vagus nerve in atropine-treated and propranolol-treated guinea pigs caused a 38.1% decrease in dynamic compliance (Cdyn), which was suppressed by the combination of the tachykinin NK1-receptor antagonist (+/-)-CP-96345 and NK2-receptor antagonist SR 48968. KW-4679 at a dose of 3 mg/kg significantly reduced the decrease in Cdyn (P < 0.05). On the other hand, KW-4679 did not inhibit substance P or neurokinin A-induced decrease in Cdyn. These results suggest that KW-4679 may inhibit the tachykininergic airway response by prejunctional inhibition of peripheral sensory nerves.