Effect of an inhaled histamine H3-receptor agonist on airway responses to sodium metabisulphite in asthma.

Abstract

Histamine H3-receptor agonists inhibit excitatory neuro-transmission in human and guinea-pig airways. Since neural bronchoconstriction may be important in asthma we have studied the effect of a specific H3-receptor agonist R-alpha-methylhistamine (alpha MeHA) on bronchoconstriction induced by the inhaled irritant sodium metabisulphite (MBS) in six mild asthmatic subjects in a randomised double-blind crossover study. Subjects received either alpha MeHA, 10 mg (as a chloride salt) or matched placebo (P) and were then challenged with doubling concentrations of MBS (0.3-80 mg ml-1) nebulised from a dosimeter at 5 min intervals with measurement of specific airway conductance (sGaw) and FEV1 at 2 and 4 min respectively after each inhalation. There was no effect of alpha MeHA on baseline airway calibre and the log concentrations of MBS required to lower sGaw by 50% (log PC50) and FEV1 by 20% (log PC20) were not significantly different after alpha MeHA when compared with placebo, suggesting that selective stimulation of airway H3-receptors does not inhibit MBS-induced bronchoconstriction.

• Authors: B J O'Connor, J M Lecomte, P J Barnes
• Journal: British journal of clinical pharmacology (Br J Clin Pharmacol) Vol. 35 Issue 1 Pg. 55-7 (Jan 1993) ISSN: 0306-5251 [Print] England
• PMID: 8448069 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Histamine Agonists
• Methylhistamines
• Receptors, Histamine
• Sulfites
• sodium metabisulfite
• alpha-methylhistamine

Topics

• Administration, Inhalation
• Adult
• Asthma (physiopathology)
• Bronchial Provocation Tests
• Bronchoconstriction (drug effects)
• Histamine Agonists (administration & dosage, pharmacology)
• Humans
• Methylhistamines (administration & dosage, pharmacology)
• Middle Aged
• Receptors, Histamine (drug effects)
• Sulfites