Der Wirkungsmechanismus von Serotonin (5-Hydroxytryptamin) und Histamin bei der Atemwegsobstruktion

Self Cite

The experiments on dogs show that the bronchoconstriction after acetylcholine inhalation is caused by a reflex mechanism mediated via sensory receptors and N. vagi. Blockade of the N. vagi with low concentration of Novocain does not affect tidal volume and frequency but blocks the acetylcholine-induced bronchoconstriction. Higher concentration of Novocain, like vagotomy, also decreases the breathing frequency and increases the tidal volume.The arterial blood gases following acetylcholine inhalation are probably more influenced by the changes on the peripheral airways than by the influence on the more central airways which are more important for the airway resistance

unclassified

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Die Azetylcholinempfindlichkeit des Bronchialbaumes

Ulmer¹,

Islam²

1974

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“…There are few reports that inhalation of aerosolized 5-HT does not induce bronchospasm in normal subjects, but can elicit severe attack in asthmatic patients [18]. However, we have previously seen [20,21] that 5-HT aerosol can provoke broncho spasm and can also sensitize the airway of dogs. Our results corroborate the concept proposed by Comroe et al [10] that 5-HT induces broncho spasm reflexly, involving the vagus nerves, since atropine at a dose of 2 mg intravenously can completely block this effect.…”

Section: Discussionmentioning

confidence: 67%

Role of Atropine in Antagonizing the Effect of 5-Hydroxytryptamine (5-HT) on Bronchial and Pulmonary Vascular Systems

Islam¹,

Melville²,

Ulmer³

1974

Self Cite

Bronchoconstrictions of equal magnitudes were induced by 5-HT when given directly by the pulmonary artery or when inhaled as aerosol. The increase artery pressure was greater when 5-HT was infused directly into the pulmonary artery. Intravenous application of atropine was always found to be effective in blocking the bronchospasm, but not the pulmonary vasoconstrictive action. It has been concluded that 5-HT induced bronchoconstriction reflexly, whereas the mode of 5-HT action on the pulmonary vascular system is not due to a reflex involving vagal pathways. The cause of the different blood gas changes are also discussed

“…[ Islam et al, 1971;Islam and Ulmer, 1973]. On the other hand, Ascaris extract aerosol has been demonstrated to have also a sensi tising effect on the bronchial system against inhalation of substances like histamine and ACH [Zimmermann andUlmer, 1976,1977].…”

mentioning

confidence: 99%

Influence of Low Concentrations of Allergens on Bronchial System

Zimmermann¹,

Ulmer²

1978

Self Cite

The influence of Ascaris extract, applied during 1 h in low concentration as aerosol and intravenously, on the bronchial system and the potentiation of increase of airway resistance to acetylcholine (ACH) and histamine challenge caused by this kind of allergen exposure were studied in 13 dogs. All the animals presented no reaction by the allergen exposure itself but developed an increased response to ACH and histamine after this kind of allergen exposure. A control group of 4 dogs was submitted to saline solution aerosol and intravenous application. No change in response to the substances mentioned was observed. The airway response to cold air after concentrated and diluted Ascaris suum extract (AE) aerosol application was tested on 7 dogs. The response to cold air was only influenced after concentrated AE-aerosol exposure.