Journal of Applied Physiology, Vol 64, Issue 5 1817-1822, Copyright © 1988 by American Physiological Society

ARTICLES

Nonadrenergic bronchodilator mechanisms in normal human subjects in vivo

J. W. Lammers, P. Minette, M. T. McCusker, K. F. Chung and P. J. Barnes
Department of Thoracic Medicine, Brompton Hospital, London.

In seven normal subjects we investigated whether a nonadrenergic bronchodilator nervous system is demonstrable in humans in vivo. After inhalation of leukotriene D4 (LTD4), respiratory resistance (Rrs) increased by 115 +/- 11% (SE). Subsequent inhalation of 2 nmol of capsaicin induced coughing and a fall in Rrs of 22.1 +/- 2% (P less than 0.01). However, inhalation of the diluent of capsaicin, 10% saline-ethanol, decreased Rrs similarly. These bronchodilator responses were not altered by inhaled ipratropium bromide (120 micrograms) and oral propranolol (80 mg). After ipratropium and propranolol, voluntary coughing alone decreased Rrs by 25 +/- 3% (P less than 0.05). We next investigated whether these bronchodilator responses could be blocked by anesthesia of the airways with inhaled lidocaine. After inhalation of lidocaine and LTD4, capsaicin aerosol induced coughing and a transient increase in Rrs of 18 +/- 6% (P less than 0.05) but no bronchodilation. Inhalation of saline-ethanol (n = 4) and a deep inhalation (n = 6) decreased Rrs by 18 +/- 4% (P less than 0.05) and 34 +/- 3% (P less than 0.001), respectively. We conclude that in normal subjects a nonadrenergic, noncholinergic bronchodilator mechanism exists, which can be activated by inhalation of capsaicin and inhibited by local anesthesia.

This article has been cited by other articles:

				P. V. Dicpinigaitis and R. V. Alva Safety of Capsaicin Cough Challenge Testing Chest, July 1, 2005; 128(1): 196 - 202. [Abstract] [Full Text] [PDF]

				S. L. Tilley, J. M. Hartney, C. J. Erikson, C. Jania, M. Nguyen, J. Stock, J. McNeisch, C. Valancius, R. A. Panettieri Jr., R. B. Penn, et al. Receptors and pathways mediating the effects of prostaglandin E2 on airway tone Am J Physiol Lung Cell Mol Physiol, April 1, 2003; 284(4): L599 - L606. [Abstract] [Full Text] [PDF]

				J. L. Szarek, B. Spurlock, C. A. Gruetter, and S. Lemke Substance P and capsaicin release prostaglandin E2 from rat intrapulmonary bronchi Am J Physiol Lung Cell Mol Physiol, November 1, 1998; 275(5): L1006 - L1012. [Abstract] [Full Text] [PDF]

				J. G. WIDDICOMBE Autonomic Regulation . i-NANC/e-NANC Am. J. Respir. Crit. Care Med., November 1, 1998; 158(2007): S171 - S175. [Abstract] [Full Text] [PDF]

				F.-X. Zhu, X.-Y. Zhang, M. A. Olszewski, and N. E. Robinson Mechanism of capsaicin-induced relaxation in equine tracheal smooth muscle Am J Physiol Lung Cell Mol Physiol, November 1, 1997; 273(5): L997 - L1001. [Abstract] [Full Text] [PDF]

				M. MIURA, H. YAMAUCHI, M. ICHINOSE, Y. OHUCHI, N. KAGEYAMA, M. TOMAKI, N. ENDOH, and K. SHIRATO Impairment of Neural Nitric Oxide-mediated Relaxation after Antigen Exposure in Guinea Pig Airways in vitro Am. J. Respir. Crit. Care Med., July 1, 1997; 156(1): 217 - 222. [Abstract] [Full Text]