Influence of chemoreceptor stimuli on genioglossal response to negative pressure in humans

Steven Shea, Toshiki Akahoshi, Jill K. Edwards, David P. White

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Genioglossal muscle (GG) activity is modulated by both chemoreceptive and mechanoreceptive reflexes that help stabilize airway patency. We assessed the effects of blood gas changes, within the range encountered during mild obstructive apnea-arousal cycles, on GG activity and the GG reflex to upper airway negative pressure. Eighteen healthy adults were studied while awake under 5 conditions: (1) baseline (PET(CO2) = 40 mm Hg, Sa(O2) = 99%); (2) hypercapnia (PET(CO2) = 45 mm Hg); (3) hypocapnia (PET(CO2) = 35 mm Hg, induced via hyperventilation with an iron lung ventilator); (4) hypoxia (Sa(O2) = 87%); and (5) hypercapnia plus hypoxia (PET(CO2) = 45 mm Hg, Sa(O2) = 87%). Measurements included airflow, choanal and epiglottic pressures (Pchoa and Pepi), upper airway resistance, phasic and tonic GG EMG, and the GG reflex to negative pressure (Pchoa = -12.5 cm H2O). Ventilation increased from a baseline of 10.7 up to 22.7 L · min-1 under conditions of altered blood gases. Peak inspiratory phasic GG EMG increased from 6.5 to 11.1% of maximal contraction but there were no significant changes in either tonic GG EMG (range, 4.3 to 5.8% of maximum) or magnitude of the GG reflex (range, 4.1 to 5.5% of maximum). Among conditions there was a high correlation between upper airway pressures and peak phasic GG EMG (Pchoa, r = 0.97, p <0.01; Pepi, r = 0.87; p = 0.06). We conclude that in this range of blood gases: (1) the GG reflex to negative pressure is unchanged; (2) slow airway pressure changes throughout inspiration, generated either actively or passively, influence GG EMG activity; and (3) mechanoreceptive control of GG EMG can fully explain all changes in GG activity, suggesting that chemoreceptive inputs to GG are minimal, or are not simply summated with mechanoreceptor inputs.

Original languageEnglish (US)
Pages (from-to)559-565
Number of pages7
JournalAmerican Journal of Respiratory and Critical Care Medicine
Volume162
Issue number2 I
StatePublished - 2000
Externally publishedYes

Fingerprint

Pressure
Muscles
Reflex
Hypercapnia
Gases
Hypocapnia
Mechanoreceptors
Airway Resistance
Hyperventilation
Apnea
Mechanical Ventilators
Arousal
Ventilation
Iron
Lung

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

Cite this

Influence of chemoreceptor stimuli on genioglossal response to negative pressure in humans. / Shea, Steven; Akahoshi, Toshiki; Edwards, Jill K.; White, David P.

In: American Journal of Respiratory and Critical Care Medicine, Vol. 162, No. 2 I, 2000, p. 559-565.

Research output: Contribution to journalArticle

@article{be7702aefde64acf978b17bd5905bed4,
title = "Influence of chemoreceptor stimuli on genioglossal response to negative pressure in humans",
abstract = "Genioglossal muscle (GG) activity is modulated by both chemoreceptive and mechanoreceptive reflexes that help stabilize airway patency. We assessed the effects of blood gas changes, within the range encountered during mild obstructive apnea-arousal cycles, on GG activity and the GG reflex to upper airway negative pressure. Eighteen healthy adults were studied while awake under 5 conditions: (1) baseline (PET(CO2) = 40 mm Hg, Sa(O2) = 99{\%}); (2) hypercapnia (PET(CO2) = 45 mm Hg); (3) hypocapnia (PET(CO2) = 35 mm Hg, induced via hyperventilation with an iron lung ventilator); (4) hypoxia (Sa(O2) = 87{\%}); and (5) hypercapnia plus hypoxia (PET(CO2) = 45 mm Hg, Sa(O2) = 87{\%}). Measurements included airflow, choanal and epiglottic pressures (Pchoa and Pepi), upper airway resistance, phasic and tonic GG EMG, and the GG reflex to negative pressure (Pchoa = -12.5 cm H2O). Ventilation increased from a baseline of 10.7 up to 22.7 L · min-1 under conditions of altered blood gases. Peak inspiratory phasic GG EMG increased from 6.5 to 11.1{\%} of maximal contraction but there were no significant changes in either tonic GG EMG (range, 4.3 to 5.8{\%} of maximum) or magnitude of the GG reflex (range, 4.1 to 5.5{\%} of maximum). Among conditions there was a high correlation between upper airway pressures and peak phasic GG EMG (Pchoa, r = 0.97, p <0.01; Pepi, r = 0.87; p = 0.06). We conclude that in this range of blood gases: (1) the GG reflex to negative pressure is unchanged; (2) slow airway pressure changes throughout inspiration, generated either actively or passively, influence GG EMG activity; and (3) mechanoreceptive control of GG EMG can fully explain all changes in GG activity, suggesting that chemoreceptive inputs to GG are minimal, or are not simply summated with mechanoreceptor inputs.",
author = "Steven Shea and Toshiki Akahoshi and Edwards, {Jill K.} and White, {David P.}",
year = "2000",
language = "English (US)",
volume = "162",
pages = "559--565",
journal = "American Journal of Respiratory and Critical Care Medicine",
issn = "1073-449X",
publisher = "American Thoracic Society",
number = "2 I",

}

TY - JOUR

T1 - Influence of chemoreceptor stimuli on genioglossal response to negative pressure in humans

AU - Shea, Steven

AU - Akahoshi, Toshiki

AU - Edwards, Jill K.

AU - White, David P.

PY - 2000

Y1 - 2000

N2 - Genioglossal muscle (GG) activity is modulated by both chemoreceptive and mechanoreceptive reflexes that help stabilize airway patency. We assessed the effects of blood gas changes, within the range encountered during mild obstructive apnea-arousal cycles, on GG activity and the GG reflex to upper airway negative pressure. Eighteen healthy adults were studied while awake under 5 conditions: (1) baseline (PET(CO2) = 40 mm Hg, Sa(O2) = 99%); (2) hypercapnia (PET(CO2) = 45 mm Hg); (3) hypocapnia (PET(CO2) = 35 mm Hg, induced via hyperventilation with an iron lung ventilator); (4) hypoxia (Sa(O2) = 87%); and (5) hypercapnia plus hypoxia (PET(CO2) = 45 mm Hg, Sa(O2) = 87%). Measurements included airflow, choanal and epiglottic pressures (Pchoa and Pepi), upper airway resistance, phasic and tonic GG EMG, and the GG reflex to negative pressure (Pchoa = -12.5 cm H2O). Ventilation increased from a baseline of 10.7 up to 22.7 L · min-1 under conditions of altered blood gases. Peak inspiratory phasic GG EMG increased from 6.5 to 11.1% of maximal contraction but there were no significant changes in either tonic GG EMG (range, 4.3 to 5.8% of maximum) or magnitude of the GG reflex (range, 4.1 to 5.5% of maximum). Among conditions there was a high correlation between upper airway pressures and peak phasic GG EMG (Pchoa, r = 0.97, p <0.01; Pepi, r = 0.87; p = 0.06). We conclude that in this range of blood gases: (1) the GG reflex to negative pressure is unchanged; (2) slow airway pressure changes throughout inspiration, generated either actively or passively, influence GG EMG activity; and (3) mechanoreceptive control of GG EMG can fully explain all changes in GG activity, suggesting that chemoreceptive inputs to GG are minimal, or are not simply summated with mechanoreceptor inputs.

AB - Genioglossal muscle (GG) activity is modulated by both chemoreceptive and mechanoreceptive reflexes that help stabilize airway patency. We assessed the effects of blood gas changes, within the range encountered during mild obstructive apnea-arousal cycles, on GG activity and the GG reflex to upper airway negative pressure. Eighteen healthy adults were studied while awake under 5 conditions: (1) baseline (PET(CO2) = 40 mm Hg, Sa(O2) = 99%); (2) hypercapnia (PET(CO2) = 45 mm Hg); (3) hypocapnia (PET(CO2) = 35 mm Hg, induced via hyperventilation with an iron lung ventilator); (4) hypoxia (Sa(O2) = 87%); and (5) hypercapnia plus hypoxia (PET(CO2) = 45 mm Hg, Sa(O2) = 87%). Measurements included airflow, choanal and epiglottic pressures (Pchoa and Pepi), upper airway resistance, phasic and tonic GG EMG, and the GG reflex to negative pressure (Pchoa = -12.5 cm H2O). Ventilation increased from a baseline of 10.7 up to 22.7 L · min-1 under conditions of altered blood gases. Peak inspiratory phasic GG EMG increased from 6.5 to 11.1% of maximal contraction but there were no significant changes in either tonic GG EMG (range, 4.3 to 5.8% of maximum) or magnitude of the GG reflex (range, 4.1 to 5.5% of maximum). Among conditions there was a high correlation between upper airway pressures and peak phasic GG EMG (Pchoa, r = 0.97, p <0.01; Pepi, r = 0.87; p = 0.06). We conclude that in this range of blood gases: (1) the GG reflex to negative pressure is unchanged; (2) slow airway pressure changes throughout inspiration, generated either actively or passively, influence GG EMG activity; and (3) mechanoreceptive control of GG EMG can fully explain all changes in GG activity, suggesting that chemoreceptive inputs to GG are minimal, or are not simply summated with mechanoreceptor inputs.

UR - http://www.scopus.com/inward/record.url?scp=0033841224&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033841224&partnerID=8YFLogxK

M3 - Article

C2 - 10934087

AN - SCOPUS:0033841224

VL - 162

SP - 559

EP - 565

JO - American Journal of Respiratory and Critical Care Medicine

JF - American Journal of Respiratory and Critical Care Medicine

SN - 1073-449X

IS - 2 I

ER -