The 5-lipoxygenase inhibitory activity of zileuton in in vitro and in vivo models of antigen-induced airway anaphylaxis.

Article Details

Citation
Copy to clipboard

Malo PE, Bell RL, Shaughnessy TK, Summers JB, Brooks DW, Carter GW

The 5-lipoxygenase inhibitory activity of zileuton in in vitro and in vivo models of antigen-induced airway anaphylaxis.

Pulm Pharmacol. 1994 Apr;7(2):73-9.

PubMed ID
8081074 [ View in PubMed
]
Abstract

Leukotrienes are biologically active lipid mediators capable of producing airway inflammation, hyperresponsiveness and bronchoconstriction. The first enzyme in the metabolic pathway of arachidonic acid leading to the leukotrienes is 5-lipoxygenase (5-LO). A selective and potent 5-LO inhibitor, zileuton (N-1(1-benzo[b]thien-2-ylethyl)-N-hydroxyurea, A-64077) was evaluated in models of airway anaphylaxis, where leukotrienes are a major component. In vitro, zileuton inhibited antigen-induced contractions of guinea-pig tracheal strips (GPTS) from actively sensitized animals with an IC50 of 6 microM. Similar results were obtained in human bronchial strips passively sensitized to IgE. Zileuton had little or no effect on contractions elicited by acetylcholine, prostaglandin D2 (PGD2), or the thromboxane agonist, U-44069. In anesthetized sensitized guinea-pigs pretreated with meclofenamic acid and mepyramine, a single aerosol exposure of antigen produced a substantial decrease in dynamic lung compliance (Cdyn). These profound changes in lung function were dose-dependently inhibited by orally administered zileuton (ED50 = 12 mg/kg). These results demonstrate that zileuton is a potent, selective inhibitor of in vitro contraction of GPTS and antigen-induced bronchoconstriction in vivo. These data also confirm the participation of 5-LO products in these models of airway anaphylaxis and suggest the usefulness of the guinea-pig for identifying and characterizing the pulmonary effects of 5-LO inhibitors.

DrugBank Data that Cites this Article

Drugs