ovalbumin and pemirolast

We established a new and facile model to investigate allergic mechanism and assess the effect of antiallergic compounds. Male Wistar rats were actively or passively sensitized. Active sensitization was performed by injection of both dinitrophenylated-ovalbumin (DNP-OA) and Bordetella pertussis. Nine days later, DNP-OA was injected into the right hind footpad. This antigen challenge induced a biphasic footpad swelling that consisted of an early-phase (EPR) and a late-phase response (LPR). In rats passively sensitized with rat anti-DNP-OA serum, DNP-OA induced only EPR. The EPR was suppressed by disodium cromoglycate, a mast cell stabilizer, but not by cyclosporin A, an immunosuppressant, while the LPR was suppressed by cyclosporin A. Furthermore, to investigate these two allergic responses determined by the interactions between the hapten and the carrier proteins, two distinct haptenated antigens were created. DNP-Ascaris (DNP-As) induced a marked EPR and LPR in DNP-As-sensitized rats. However, DNP-As induced only EPR in DNP-OA-sensitized rats, indicating that the usage of the same carrier protein in both sensitization and challenge was necessary for induction of LPR. These data suggest that this actively sensitization model in which EPR and LPR are functionally distinguishable should be useful for evaluating the efficacy of antiallergic compounds.

Topics: Aminopyridines; Animals; Anti-Allergic Agents; Antigens; Cromolyn Sodium; Cyclosporine; Dinitrobenzenes; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Evaluation, Preclinical; Edema; Haptens; Hindlimb; Hypersensitivity, Delayed; Male; ortho-Aminobenzoates; Ovalbumin; Passive Cutaneous Anaphylaxis; Promethazine; Pyridines; Pyrimidinones; Quinolones; Rats; Rats, Wistar

To investigate the development of airway hyperresponsiveness in infantile guinea pigs, animals (10 days old) were immunized twice and challenged by inhalation of 1% ovalbumin for 10 min with 7 days intervals. Similar to adult guinea pigs, infantile ones developed an increased airway responsiveness to acetylcholine 24 hr after antigen challenge. There was a marked increase in the number of total leukocytes, eosinophils and lymphocytes in bronchoalveolar lavage fluid (BALF). Suplatast tosilate (suplatast) and pemirolast potassium (pemirolast) given orally throughout the experiments suppressed the development of airway hyperresponsiveness in infantile animals. They showed similar potency in the suppression of eosinophil accumulation in BALF and lung tissue, while suplatast inhibited lymphocyte accumulation stronger than pemirolast. Collectively, the present model of airway hyperresponsiveness in infantile guinea pigs may be useful in predicting the efficacy of antiallergic agents in the treatment of asthmatic children.

Topics: Animals; Anti-Allergic Agents; Antigens; Arylsulfonates; Asthma; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Guinea Pigs; Histamine Antagonists; Leukocyte Count; Male; Ovalbumin; Pyridines; Pyrimidinones; Respiratory Hypersensitivity; Sulfonium Compounds