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  • 1
    ISSN: 1420-908X
    Keywords: Key words: Allergic conjunctivitis — Itching — Pollenosis — IgE — Allergic model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: To develop a model of experimental allergic conjunctivitis, guinea pigs were given repetitive and topical applications of Japanese cedar pollen as an antigen, and the resulting allergic reaction was characterised.¶Subjects: Male Hartley guinea pigs.¶Treatment: Guinea pigs were sensitised by insertion of small gelatin sponge pieces (3 pieces/eye, both eyes) containing the pollen extracts + Al(OH)3 into the palpebra superior/inferior sulci of both eyes for 8 h/day for 6 days. Then the animals were challenged by dropping pollen suspension in each eye once every week.¶Methods: Time-course changes of conjunctivitis intensity score (CIS), which represents oedema and redness, and scratching frequency, and γ1 and IgE levels in sera were assessed following the respective 1st-17th challenges. Ophthalmic lavage was performed to assay for albumin leakage and migrated leukocytes at each of the odd-numbered challenges.¶Results: At relatively early stages of the repeated challenge, only a gradual increase of CIS was observed. However, thereafter, considerably higher CIS with the maximum at 30 min after the challenge was provoked at the 12th-17th challenges. Quite interestingly, there were differences in the CIS between the right and left eyes, depending on the individuals. Scratching, and albumin leakage and neutrophil influx into the lavage fluid were also developed during the challenges. Although the anaphylactic antibodies against the antigen were detected in the sera from half of the animals, the levels were not correlated to severity of the symptoms.¶Conclusions: The present sensitisation/challenge procedures are unique in terms of topical application of antigen. The lack of any correlation between the levels of the anaphylactic antibodies and severity of anaphylactic symptoms, and the difference of CIS between the left and right eyes of an individual strongly suggest that the anaphylactic antibodies are formed in locally limited tissue surrounding an eye. The present method should be useful for analysing the mechanisms of allergic conjunctivitis.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1420-908X
    Keywords: Key words: Ephedrine – Stomach – Passive cutaneous anaphylaxis – Adrenergic nerve – Adrenoceptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: We previously demonstrated that oral l-ephedrine exerts an extremely rapid (within 20 s) inhibition of 48-h passive cutaneous anaphylaxis reaction (PCA) in rats by a possibly unidentified mode of action. In the present experiments, we elucidated the mechanism of the PCA inhibition by l-ephedrine using adrenoceptor agonists and antagonists.¶Materials: Rat antiserum was prepared with dinitrophenylated Ascaris suum extract + Bordetella pertussis.¶Treatment: Passively skin-sensitised Wistar rats were mainly used. l-Ephedrine, and adrenoceptor agonists and antagonists were orally administered immediately before PCA provocation. Catecholamine depleting (6-hydroxydopamine, 6-OH-DA), amine depleting (reserpine) or ganglion blocking (hexamethonium) agent was intraperitoneally or intravenously administered before the provocation.¶Methods: The effects of the drugs on PCA were assessed by inhibition of the dye leakage.¶Results: β-(propranolol) and β 2-(butoxamine) blocking agents reduced the inhibition of PCA by l-ephedrine, while the inhibition was not altered by either an α-blocking agent (phentolamine) or a β 1-(atenolol) selective antagonist. On the other hand, β-(isoproterenol) and β 2-selective (salbutamol) agonists showed extremely rapid inhibition of PCA. However, the β 1-selective agonist (dobutamine) had no effect on the reaction. The pretreatment with hexamethonium, reserpine or 6-OH-DA substantially attenuated the inhibitory effect of l-ephedrine on PCA.¶Conclusions: The results strongly suggest that β 2-adrenoceptors locate in the stomach and that their receptor excitement finally may lead to the inhibition of PCA via the stimulation of the central and peripheral nervous systems.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1420-908X
    Keywords: Key words: Ephedrine - Ephedra herb - Passive cutaneous anaphylaxis - Mast cell - Histamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract: Objective and Design: Whether Mao-Bushi-Saishin-To (MBST), one of the formulas of classical Chinese medicine, is effective on 48-h passive cutaneous anaphylaxis (PCA) in rats and which substance in the formula is responsible for its inhibitory action were examined.¶Treatment: In the studies on PCA, MBST (hot water extract of the whole herbal formula), extracts of Ephedra herb (Mao), l-ephedrine and other reference drugs were orally administered immediately or at various times before or 5 min after the antigen challenge. In the experiments on anaphylactic histamine release from rat peritoneal mast cells, l-ephedrine and d-pseudoephedrine were added at 10-4-10-7 g/ml at 30, 10, 3 or 0 min before antigen provocation.¶Results: The time course study indicated that MBST produced a prompt and long lasting inhibition of PCA. Among the constituents of Mao, l-ephedrine exerted this prompt inhibitory activity, but d-pseudoephedrine did not. Neither pseudoephedrine nor l-ephedrine prevented the anaphylactic histamine release from isolated peritoneal mast cells.¶Conclusions: It is strongly emphasised that the rapid suppression of PCA by orally administered l-ephedrine must be exerted by a mechanism distinct from that of suppression produced following gastrointestinal absorption of the drug, because the time required for the inhibition was extraordinarily short. However, direct inhibition of anaphylactic histamine release from isolated mast cells was excluded in this inhibition of PCA.¶
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1420-908X
    Keywords: Key words: Allergic rhinitis — Nasal blockage — Sneeze — Pollen — Airway resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: Development of nasal blockage and sneezing during repeated inhalation challenges with Japanese cedar pollens was evaluated in guinea pigs.¶Subjects: Male Hartley guinea pigs.¶Treatment: Guinea pigs were sensitized by intranasal instillation of cedar pollen extracts + Al(OH)3 2 times a day for 7 days. The animal was then forced to inhale the pollens for challenge, which was restrictively trapped in the upper airways, once a week.¶Methods: Change of specific airway resistance (sRaw), sneezing frequency, and titers of anaphylactic antibodies in the serum were measured after each of the 30 challenges.¶Results: At the first challenge, no obvious increase in sRaw was observed. However, the second and third challenges to the animals caused modest biphasic elevations of sRaw, with peaks at the first and the fourth to sixth hour. At the fourth to tenth challenges, marked elevations of sRaw were observed. However, with repetition of the inhalation challenge, the early and the late responses became almost indistinguishable because of partial overlapping as the responses expanded. All guinea pigs sneezed immediately after each pollen inhalation challenge. Apparent increases of both circulating γ1 and IgE antibodies were seen after the seventh challenge.¶Conclusions: These results indicate that the experimental allergic rhinitis established in the present study can be a valuable model for analyzing the pathogenesis of the disease and developing new therapeutic drugs.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1420-908X
    Keywords: Key words: Ephedrine - Passive cutaneous anaphylaxis - Mast cell - Vascular permeability - Histamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract: Objective and Design: We previously reported that oral l-ephedrine showed extraordinarily rapid inhibition of 48-h passive cutaneous anaphylaxis (PCA) in rats. In the present study, in vivo and in vitro experiments were performed to elucidate a possible mechanism for the inhibition.¶Materials: Rat antiserum was prepared with dinitrophenylated Ascaris suum extract + Bordetella pertussis.¶Treatment: Wistar rats were passively skin-sensitised, actively sensitised or non-sensitised. l-Ephedrine immediately before provocations was orally or intravenously administered in in vivo experiments. In in vitro experiments, the drug was added at various time and concentrations before the challenge.¶Methods: The intensity of PCA was assessed by dye leakage method. Histamine and serotonin released in vitro or retained in the skin in vivo by anaphylaxis were assayed fluorometrically.¶Results: Oral l-ephedrine rapidly inhibited the PCA by inhibiting the release of histamine and serotonin from the reaction site, whereas anaphylactic histamine and serotonin releases from skin fragments were not affected by the drug. Furthermore, the orally administered drug influenced neither the histamine- nor serotonin-induced cutaneous vascular permeability.¶Conclusions: These results were strongly indicative that the prompt suppression of the PCA by oral l-ephedrine was not exerted following the drug was absorbed from the gastrointestinal tract. Thus, the result may be from an indirect inhibition of chemical mediator release, possibly through an unidentified stimulation of the nervous system, but not from the inhibition of chemical mediator release by the direct interaction of drug to mast cells and not from the decreased vascular permeability.¶
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Clinical & experimental allergy 32 (2002), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Allergic airway eosinophilia is suppressed by cysteinyl leukotriene (CysLT) receptor (CysLT1 receptor) antagonists in several species including humans and guinea-pigs, suggesting that CysLTs are directly or indirectly involved in induction of the response.Objective We examined the effect of CysLT antagonists (pranlukast and MCI-826) on antigen inhalation-induced eosinophilia in peripheral blood and lung, and on IL-5 activity in serum during late increase of airway resistance (late asthmatic response, LAR) in sensitized guinea-pigs.Methods Guinea-pigs inhaled ovalbumin (OVA) + Al(OH)3 and OVA mists alternately for sensitization and challenge, respectively, once every 2 weeks. At the fifth challenge, the effects of CysLT antagonists and an anti-IL-5 antibody (TRFK-5) on the occurrence of LAR, and blood and lung eosinophilia, which appeared at 5 h after challenge, were examined. The time-course of IL-5 activity in the serum after the challenge was evaluated by measuring in vitro‘eosinophil survival prolongation activity’. The influence of CysLT antagonists on IL-5 activity was assessed.Results CysLT antagonists and TRFK-5 completely abolished blood and lung eosinophilia. LAR was suppressed by both MCI-826 and TRFK-5 by 40–50%. Sera obtained from sensitized, challenged animals 3 h and 4 h after challenge induced an obvious prolongation of eosinophil survival. The activity of the sera was completely neutralized by prior exposure to TRFK-5, suggesting that it reflected IL-5 activity. Increased IL-5 activity in the serum was inhibited by both pranlukast and MCI-826 by over 90%.Conclusions CysLTs produced after antigen provocation sequentially induced IL-5 production from some immune component cells via CysLT1 receptor activation. Thus, it is likely that CysLTs indirectly cause antigen-induced eosinophilia through IL-5 production.
    Type of Medium: Electronic Resource
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