Modulation of capsaicin induced airway reflexes in humans: effect of monoamine oxidase inhibition.

Abstract

1. In animal studies monoamine oxidase (MAO) inhibition has been shown to reduce the cough response through elevation of 5-HT in the central nervous system. In this study the effect of selective inhibition of the two subtypes of MAO (MAO-A and MAO-B) was studied on human airway reflexes. 2. Capsaicin-induced cough and reflex increase in respiratory resistance were measured in nine normal volunteers before and after MDL 72394 (MAO-A inhibitor) 16 mg or MDL 72974A (MAO-B inhibitor) 12 mg. 3. Neither inhibitor altered capsaicin-induced cough. Following treatment with MDL 72394, however, the capsaicin-induced reflex increase in resistance was enhanced, by 5.97 +/- 2.1 fold of the placebo value at 1 h. 4. Thus, neurotransmitters in the central nervous system which are substrate for MAO-A (i.e. noradrenaline, 5-HT) may be involved in the control of capsaicin-induced reflex bronchoconstriction.

• Authors: N B Choudry, J Studham, D Harland, R W Fuller
• Journal: British journal of clinical pharmacology (Br J Clin Pharmacol) Vol. 35 Issue 2 Pg. 184-7 (Feb 1993) ISSN: 0306-5251 [Print] England
• PMID: 8443037 (Publication Type: Clinical Trial, Controlled Clinical Trial, Journal Article)

Chemical References

• Allyl Compounds
• Butylamines
• Monoamine Oxidase Inhibitors
• mofegiline
• Tyrosine
• beta-fluoromethylene-3-tyrosine
• Capsaicin

Topics

• Adult
• Airway Resistance (drug effects)
• Allyl Compounds
• Analysis of Variance
• Bronchoconstriction (drug effects)
• Butylamines (pharmacology)
• Capsaicin (pharmacology)
• Cough (chemically induced)
• Humans
• Male
• Monoamine Oxidase Inhibitors (administration & dosage, pharmacology)
• Tyrosine (administration & dosage, analogs & derivatives, pharmacology)