Reflex decrease of histamine-induced bronchoconstriction after laryngeal stimulation in humans

Am Rev Respir Dis. 1987 Sep;136(3):618-22. doi: 10.1164/ajrccm/136.3.618.


The aim of this work was to determine whether the nonadrenergic, noncholinergic, inhibitory nervous system can be reflexly activated in humans by laryngeal stimulation. The stimulation was achieved with a cytology brush passed through a bronchoscope previously introduced transnasally and positioned just above the epiglottis. In one series of experiments, subjects were premedicated with beta-adrenergic and cholinergic blockers, and bronchoconstriction was induced by histamine inhalation. The results showed that mechanical irritation of the vocal cords with the cytology brush produced a sharp, short-lasting (less than 1 min) decrease in RL from (mean +/- SE) 6.8 +/- 2.1 to 4.8 +/- 1.5 cm H2O.L-1.s, and in the absence of parasympathetic blockade, laryngeal irritation produced a fall in RL from (mean +/- SE) 9.0 +/- 3.7 to 5.4 +/- 2.0 cm H2O.L-1.s (p less than 0.0001) (ANOVA). This decrease in RL was independent of the slight cough produced by laryngeal stimulation and reflects a change in lower and not upper airway resistance. Adequacy of the beta-adrenergic and cholinergic blockade was checked with an intravenous infusion of isoproterenol and inhaled methacholine, respectively. In 2 subjects, the fall in RL was abolished by a block of the superior laryngeal nerves and direct local anesthesia of the vocal cords. We conclude that mechanical irritation of the larynx produces a partial reversal of histamine-induced bronchoconstriction that is mediated through nervous pathways that are neither beta-adrenergic nor cholinergic in origin. We suggest that this decrease in bronchoconstriction is modulated by the nonadrenergic, noncholinergic, inhibitory nervous system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Airway Resistance
  • Autonomic Nervous System / physiology*
  • Bronchial Provocation Tests*
  • Bronchial Spasm / chemically induced*
  • Bronchial Spasm / etiology
  • Cough / etiology
  • Female
  • Histamine*
  • Humans
  • Laryngeal Nerves / physiology*
  • Male
  • Neural Pathways / physiology
  • Physical Stimulation
  • Reflex / physiology*


  • Histamine