Keiichi Musoh

Participation of histamine H1 and H2 receptors in passive cutaneous anaphylaxis-induced scratching behavior in ICR mice

Scratching behavior associated with passive cutaneous anaphylaxis was examined and compared to that induced by compound 48/80 or histamine in ICR mice. Elicitation of passive cutaneous anaphylaxis, and intradermal injections of compound 48/80, histamine or serotonin induced both scratching behavior and vascular permeability increase in ICR mice. In mast cell-deficient WBB6F1-W/Wv mice, although histamine induced scratching behavior and vascular permeability increase, passive cutaneous anaphylaxis was not observed. Cetirizine and terfenadine significantly inhibited the scratching behavior and vascular permeability increase caused by passive cutaneous anaphylaxis, compound 48/80 and histamine. The histamine H1 receptor antagonists inhibited the vascular permeability increase almost completely, whereas they failed to abolish the scratching behavior. Famotidine and ranitidine significantly inhibited the scratching behavior caused by histamine. The histamine H2 receptor antagonists did not affect the vascular permeability increase caused by histamine. The combination of cetirizine and ranitidine abolished the histamine-induced scratching behavior. The combination, however, failed to potentiate the inhibition of passive cutaneous anaphylaxis-induced scratching behavior significantly. The results indicated that histamine induces scratching behavior in ICR mice through both histamine H1 and H2 receptors, and that histamine plays a major role in passive cutaneous anaphylaxis-induced scratching behavior. Histamine might also play an important role in compound 48/80-induced scratching behavior.

Evaluation of anti-scratch properties of oxatomide and epinastine in mice

Anti-scratch effects of oxatomide and epinastine were examined in mice. Scratching behavior and cutaneous reactions were induced in BALB/c, ICR and ddY mice by dinitrofluorobenzene painting, passive cutaneous anaphylaxis and substance P injection, respectively. Although oxatomide and epinastine failed to inhibit scratching behavior in BALB/c mice, they inhibited the cutaneous reaction significantly. The drugs potently inhibited both scratching behavior and cutaneous reaction in ICR mice. They also inhibited scratching behavior and cutaneous reaction in ddY mice, although cetirizine and terfenadine failed to affect them. Histamine did not induce frequent scratching behavior in BALB/c and ddY mice. These results indicate that oxatomide and epinastine inhibit the scratching behavior in ICR mice associated with passive cutaneous anaphylaxis mainly through an antagonistic action on histamine H(1) receptors. The results also indicate that these drugs inhibit substance P-induced scratching behavior in ddY mice through an action independent of the antagonistic action on histamine H(1) receptors.

TNF-α participates in an IgE-mediated cutaneous reaction in mast cell deficient, WBB6F1-W/Wv mice

The participation of tumor necrosis factor-α (TNF-α) in a IgE-mediated cutaneous reaction in WBB6F1-W/Wv (W/Wv), mast cell deficient, mice and the effect of prednisolone on this cutaneous reaction were investigated. Mice were passively sensitized by an intravenous injection of monoclonal anti-dinitrophenol (DNP) IgE, and their ears challenged epicutaneously with dinitrofluorobenzene 24 h later. The cutaneous reaction estimated by ear thickness reached a peak 48–72h after the antigen challenge. A monoclonal anti-tumor necrosis factor (TNF)-α antibody inhibited the IgE-mediated cutaneous reaction. An increase of TNF-α mRNA was demonstrated 4h after the application of antigen by the reverse transcriptase-polymerase chain reaction. The injection of recombinant murine TNF-α induced a cutaneous reaction which peaked at 24 h in nonsensitized mice. Prednisolone at doses of 3 to 10 mg/kg clearly inhibited the IgE-mediated cutaneous reaction, however, it did not affect the expression of TNF-α-mRNA. Prednisolone at doses of 1 to 10 mg/kg clearly inhibited the TNF-α-induced cutaneous reaction.These results suggest that TNF-α plays a role in the IgE-mediated cutaneous reaction in W/Wv mice and that prednisolone inhibits the cutaneous reaction at least in part by inhibiting the action of TNF-α.

Interferon-Beta Prevents Antigen-Induced Bronchial Inflammation and Airway Hyperreactivity in Mice

The effects of IFN-beta and prednisolone (Pred) on antigen-induced IgE antibody production, airway eosinophilia and airway hyperreactivity (AHR) were studied in ovalbumin-sensitized Balb/c mice. Three inhalations of antigen (ovalbumin) caused an increase in the number of eosinophils and lymphocytes in bronchoalveolar lavage fluid and AHR to acetylcholine with a significant elevation in the serum IgE level. IFN-beta clearly inhibited the antigen-induced airway inflammation and AHR, but did not affect IgE antibody production. Pred inhibited antigen-induced IgE antibody production, airway inflammation and AHR to acetylcholine. In addition, IFN-beta inhibited T-helper type 2 (Th2) cell clone (D10G4.1)-induced peritoneal eosinophilia in mice, but did not affect neutrophilia, whereas Pred inhibited D10G4.1-induced peritoneal eosinophilia and neutrophilia. These results suggest that IFN-beta inhibits antigen-induced bronchial inflammation and AHR probably due to the inhibition of Th2-induced airway eosinophilia.

Characterization of antihistamines using biphasic cutaneous reaction in BALB/c mice

Effects of 11 histamine H1 receptor antagonists on IgE-mediated biphasic cutaneous reaction in mice were examined. The immediate phase reaction (IPR) assessed at 1 hour after antigen application was significantly inhibited by all antihistamines examined. The inhibition of IPR by cetirizine and mequitazine were potent, but those by cyproheptadine and diphenhydramine were weak. The later phase reaction (LPR) assessed at 24 hours after antigen application was inhibited by chlorpheniramine, oxatomide, ketotifen, mequitazine, emedastine, terfenadine and azelastine. The inhibition of LPR by emedastine was potent, but those by ketotifen and terfenadine were only partial. Emedastine inhibited both IPR and LPR comparably. Present results indicate that H1 receptor activation is involved in the IPR of the biphasic cutaneous reaction, and that the blockade of H1 receptors at IPR does not contribute to the attenuation of following LPR. Histamine H1 receptor antagonists inhibiting the LPR have a property distinct from H1 receptor antagonism, which may have an additional benefit for the treatment of allergic diseases.

Possible Role of Nitric Oxide in IgE-Mediated Allergic Cutaneous Reaction in Mice

The role of nitric oxide (NO) in the development of allergic cutaneous reactions in mice was investigated. A biphasic cutaneous reaction composed of an immediate-phase edema and a late-phase edema was evoked by epicutaneous application of 2,4-dinitrofluorobenzene on the ear of mice passively sensitized with mouse anti-dinitrophenol monoclonal IgE. Two NO synthase inhibitors, L-NG-nitroarginine methyl ester (L-NAME) and NG-monomethyl-L-arginine, significantly inhibited both phases of the IgE-mediated biphasic cutaneous reaction. Simultaneous treatment with L-arginine attenuated the inhibitory effect of L-NAME. An NO donor, 3-morpholinosydononimine-N-ethylcarbamide, caused a potent edematous reaction in the mouse ear. Furthermore, L-NAME inhibited the cutaneous reactions caused by both interleukin-1β and tumor necrosis factor-α, putative mediators of the late-phase edema in the biphasic cutaneous reaction. These results indicate that a gaseous mediator, NO, participates, at least in part, in the development of ear edema in the IgE-mediated biphasic cutaneous reaction in mice.

Effects of RS-601, a Novel Leukotriene D4/Thromboxane A2 Dual Receptor Antagonist, on Asthmatic Responses in Guinea Pigs

The effects of 4-[4-[5,5,6,6,6-pentafluoro-1-(4-fluorobenzene-sulfonamido)hexyl]phenyl]butyric acid (RS-601), a novel leukotriene D4 (LTD4)/thromboxane A2 (TxA2) dual receptor antagonist, on bronchial asthmatic responses in guinea pigs were examined. The effects were compared with those of pranlukast (LTD4 receptor antagonist) and S-1452 (TxA2 receptor antagonist). RS-601 inhibited the increase in airway resistance caused by LTD4 and TxA2 mimetic compound, U-46619, but not by histamine. RS-601 and pranlukast but not S-1452 inhibited an antigen-induced late asthmatic response. In addition, RS-601 inhibited an antigen-induced airway hyperresponsiveness (AHR), whereas pranlukast and S-1452 had no effect on the AHR. The antigen-induced increase in inflammatory cells in airway was not affected by all examined agents. Furthermore, bacterial lipopolysaccharide-induced AHR in guinea pigs was clearly suppressed by RS-601 but not by pranlukast and S-1452. The increase in airway inflammatory cells caused by lipopolysaccharide was not affected by all three drugs. These findings indicate that RS-601 has a potent antiasthmatic efficacy, especially on AHR, but does not affect accumulation of eosinophils in the airways.

Effect of a novel anti-allergic agent, HSR-609, on antigen-induced airway hyperresponsiveness in mice

The effects of a newly synthesized anti-allergic agent, HSR-609, on allergic airway hyperresponsiveness and airway inflammation have been studied in sensitized mice. The effects were compared with those of two histamine H1 receptor antagonists, cetirizine and terfenadine, and prednisolone. Three inhalations of antigen caused an increase in leukocytes (including eosinophils) with increases in IL-5 in BALF and airway hyperresponsiveness to acetylcholine in BALB/c mice. All drugs were orally administered once a day for 10 days from the day before the first inhalation of antigen. HSR-609 (10 mg/kg) and prednisolone (5 mg/kg) significantly inhibited the antigen-induced airway hyperresponsiveness, whereas cetirizine (10 mg/kg) or terfenadine (100 mg/kg) did not affect this airway response. At the same time HSR-609 inhibited the antigen-induced eosinophilia and IL-5 production in BALF. Prednisolone also showed an inhibitory effect on the airway eosinophilia and IL-5 production but not cetirizine and terfenadine in the same experiments. In addition, HSR-609 (p.o.) dose-dependently suppressed the accumulation of eosinophils elicited by antigen-stimulated D10G4.1 cells, a murine Th2 clone, in peritoneal cavity lavage fluid in AKR/J mice. These results suggest that HSR-609 inhibits allergic airway hyperresponsiveness to acetylcholine probably because of the inhibition of Th2-dependent eosinophilia caused by IL-5. In addition, effects of HSR-609 were different from those of cetirizine and terfenadine concerning the inhibition of antigen-induced airway hyperresponsiveness in mice.

Effects of an amphoteric antiallergic agent, HSR-609, on antigen-induced late phase nasal eosinophilia in brown Norway rats.

The effect of a newly synthesized compound, HSR-609, on rat experimental rhinitis was investigated. In the first part of the study, a new experimental nasal allergic late phase eosinophilia model in Brown Norway (BN) rats was investigated. The increase in the number of antigen inhalations resulted in the proportional increase in the number of inflammatory cells such as macrophages, eosinophils and neutrophils in the nasal cavity lavage fluid (NCLF) at 5 h after each inhalation. The number of inflammatory cells reached a maximum 8 h after the antigen perfusion. Submaximum response was observed at 5 h after the antigen provocation. In this system, the serum IgG and IgE antibody titers measured by homologous passive cutaneous anaphylaxis were 160 and 640, respectively. In the second part of the study, the effects of prednisolone, cetirizine and a newly synthesized amphoteric antiallergic agent, HSR-609, on this allergic late nasal eosinophilia and neutrophilia in BN rats were investigated. Prednisolone and HSR-609 significantly inhibited the increase in the number of eosinophils in the NCLF but not cetirizine. Furthermore, prednisolone showed the inhibition of the increase in the number of macrophages and neutrophils in NCLF. These results suggest that this late phase eosinophilia model in the nose of BN rats may be useful for investigating the therapeutic drugs for nasal allergy and a newly synthesized amphoteric antiallergic agent, HSR-609, may be useful for the treatment of allergic rhinitis with eosinophilia.