Capsaicin-induced activation of pulmonary vagal C fibers produces reflex laryngeal closure in the rat

I. Jung Lu, Kun Ze Lee, Ji Chuu Hwang

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Our recent studies show that intravenous administration of capsaicin induces enhancement of the intralaryngeal thyroarytenoid (TA) branch but a reduction of the intralaryngeal abducent branch, suggesting that the glottis is likely closed by capsaicin. The aim of the present study was to examine whether the glottis is adducted by intravenous administration of capsaicin. Electromyographic (EMG) activity of the TA muscle, subglottal pressure (SGP), and glottal behavior were evaluated before and after intravenous administration of capsaicin in male Wistar rats that were anesthetized and tracheostomized. Catheters were placed in the femoral artery and vein, as well as in the right jugular vein. Low and high doses of capsaicin (0.625 and 1.25 μg/kg) produced apnea and increases in the amplitude of the TA EMG. This enhancement of the TA EMG was observed during apnea as well as during recovery from apnea. Moreover, the onset of the TA EMG was advanced such that it commenced earlier during inspiration. Concomitantly, the SGP substantially increased. Increases in both the TA EMG and SGP were abolished after bilateral sectioning of the recurrent laryngeal nerve. In some animals, movement of the vocal folds was recorded by taking a motion picture with a digital camera under a surgical microscope. With intravenous administration of capsaicin, a tight glottal closure, decreases in blood pressure, and bradycardia were observed. These results strongly suggest that glottal closure is reflexively induced by intravenous administration of capsaicin and that closure of the glottis is beneficial for the defense of the airway and lungs when an animal is exposed to environmental irritants.

Original languageEnglish
Pages (from-to)1104-1112
Number of pages9
JournalJournal of Applied Physiology
Volume101
Issue number4
DOIs
Publication statusPublished - 2006 Oct 9

Fingerprint

Unmyelinated Nerve Fibers
Capsaicin
Reflex
Intravenous Administration
Lung
Glottis
Apnea
Pressure
Laryngeal Muscles
Recurrent Laryngeal Nerve
Femoral Vein
Vocal Cords
Irritants
Jugular Veins
Femoral Artery
Motion Pictures
Bradycardia
Wistar Rats
Catheters
Blood Pressure

Keywords

  • Apnea
  • Bradycardia
  • Diaphragmatic electromyogram
  • Glottal closure
  • Subglottal pressure
  • Thyroarytenoid electromyogram

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Capsaicin-induced activation of pulmonary vagal C fibers produces reflex laryngeal closure in the rat. / Lu, I. Jung; Lee, Kun Ze; Hwang, Ji Chuu.

In: Journal of Applied Physiology, Vol. 101, No. 4, 09.10.2006, p. 1104-1112.

Research output: Contribution to journalArticle

@article{2b38ec25f2024ae494ac1e62c2f45f21,
title = "Capsaicin-induced activation of pulmonary vagal C fibers produces reflex laryngeal closure in the rat",
abstract = "Our recent studies show that intravenous administration of capsaicin induces enhancement of the intralaryngeal thyroarytenoid (TA) branch but a reduction of the intralaryngeal abducent branch, suggesting that the glottis is likely closed by capsaicin. The aim of the present study was to examine whether the glottis is adducted by intravenous administration of capsaicin. Electromyographic (EMG) activity of the TA muscle, subglottal pressure (SGP), and glottal behavior were evaluated before and after intravenous administration of capsaicin in male Wistar rats that were anesthetized and tracheostomized. Catheters were placed in the femoral artery and vein, as well as in the right jugular vein. Low and high doses of capsaicin (0.625 and 1.25 μg/kg) produced apnea and increases in the amplitude of the TA EMG. This enhancement of the TA EMG was observed during apnea as well as during recovery from apnea. Moreover, the onset of the TA EMG was advanced such that it commenced earlier during inspiration. Concomitantly, the SGP substantially increased. Increases in both the TA EMG and SGP were abolished after bilateral sectioning of the recurrent laryngeal nerve. In some animals, movement of the vocal folds was recorded by taking a motion picture with a digital camera under a surgical microscope. With intravenous administration of capsaicin, a tight glottal closure, decreases in blood pressure, and bradycardia were observed. These results strongly suggest that glottal closure is reflexively induced by intravenous administration of capsaicin and that closure of the glottis is beneficial for the defense of the airway and lungs when an animal is exposed to environmental irritants.",
keywords = "Apnea, Bradycardia, Diaphragmatic electromyogram, Glottal closure, Subglottal pressure, Thyroarytenoid electromyogram",
author = "Lu, {I. Jung} and Lee, {Kun Ze} and Hwang, {Ji Chuu}",
year = "2006",
month = "10",
day = "9",
doi = "10.1152/japplphysiol.01101.2005",
language = "English",
volume = "101",
pages = "1104--1112",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "4",

}

TY - JOUR

T1 - Capsaicin-induced activation of pulmonary vagal C fibers produces reflex laryngeal closure in the rat

AU - Lu, I. Jung

AU - Lee, Kun Ze

AU - Hwang, Ji Chuu

PY - 2006/10/9

Y1 - 2006/10/9

N2 - Our recent studies show that intravenous administration of capsaicin induces enhancement of the intralaryngeal thyroarytenoid (TA) branch but a reduction of the intralaryngeal abducent branch, suggesting that the glottis is likely closed by capsaicin. The aim of the present study was to examine whether the glottis is adducted by intravenous administration of capsaicin. Electromyographic (EMG) activity of the TA muscle, subglottal pressure (SGP), and glottal behavior were evaluated before and after intravenous administration of capsaicin in male Wistar rats that were anesthetized and tracheostomized. Catheters were placed in the femoral artery and vein, as well as in the right jugular vein. Low and high doses of capsaicin (0.625 and 1.25 μg/kg) produced apnea and increases in the amplitude of the TA EMG. This enhancement of the TA EMG was observed during apnea as well as during recovery from apnea. Moreover, the onset of the TA EMG was advanced such that it commenced earlier during inspiration. Concomitantly, the SGP substantially increased. Increases in both the TA EMG and SGP were abolished after bilateral sectioning of the recurrent laryngeal nerve. In some animals, movement of the vocal folds was recorded by taking a motion picture with a digital camera under a surgical microscope. With intravenous administration of capsaicin, a tight glottal closure, decreases in blood pressure, and bradycardia were observed. These results strongly suggest that glottal closure is reflexively induced by intravenous administration of capsaicin and that closure of the glottis is beneficial for the defense of the airway and lungs when an animal is exposed to environmental irritants.

AB - Our recent studies show that intravenous administration of capsaicin induces enhancement of the intralaryngeal thyroarytenoid (TA) branch but a reduction of the intralaryngeal abducent branch, suggesting that the glottis is likely closed by capsaicin. The aim of the present study was to examine whether the glottis is adducted by intravenous administration of capsaicin. Electromyographic (EMG) activity of the TA muscle, subglottal pressure (SGP), and glottal behavior were evaluated before and after intravenous administration of capsaicin in male Wistar rats that were anesthetized and tracheostomized. Catheters were placed in the femoral artery and vein, as well as in the right jugular vein. Low and high doses of capsaicin (0.625 and 1.25 μg/kg) produced apnea and increases in the amplitude of the TA EMG. This enhancement of the TA EMG was observed during apnea as well as during recovery from apnea. Moreover, the onset of the TA EMG was advanced such that it commenced earlier during inspiration. Concomitantly, the SGP substantially increased. Increases in both the TA EMG and SGP were abolished after bilateral sectioning of the recurrent laryngeal nerve. In some animals, movement of the vocal folds was recorded by taking a motion picture with a digital camera under a surgical microscope. With intravenous administration of capsaicin, a tight glottal closure, decreases in blood pressure, and bradycardia were observed. These results strongly suggest that glottal closure is reflexively induced by intravenous administration of capsaicin and that closure of the glottis is beneficial for the defense of the airway and lungs when an animal is exposed to environmental irritants.

KW - Apnea

KW - Bradycardia

KW - Diaphragmatic electromyogram

KW - Glottal closure

KW - Subglottal pressure

KW - Thyroarytenoid electromyogram

UR - http://www.scopus.com/inward/record.url?scp=33749335665&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749335665&partnerID=8YFLogxK

U2 - 10.1152/japplphysiol.01101.2005

DO - 10.1152/japplphysiol.01101.2005

M3 - Article

C2 - 16645190

AN - SCOPUS:33749335665

VL - 101

SP - 1104

EP - 1112

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 4

ER -