Sustained muscle sympathetic activity after hypercapnic but not hypocapnic hypoxia in normal humans

Respiratory Physiology & Neurobiology
Renaud TamisierJ Woodrow Weiss

Abstract

Exposure to hypercapnic hypoxia (asphyxia), but not hyperoxic hypercapnia, results in increased sympathetic activity that persists after exposure. To determine the contribution of CO2 to the post-hypoxia sympathoexcitation, we exposed 12 normal volunteers to hypocapnic and hypercapnic hypoxia (SaO2 approximately 85%) for 20 min each on different days. We measured plethysmographic forearm blood flow, muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate. MSNA increased during both exposures but remained elevated for 15 min only after asphyxia. Following asphyxia, MAP returned to pre-exposure values, but after hypocapnic hypoxia MAP decreased below baseline for 15 min. There were sustained decreases in heart rate after hypocapnic, but not hypercapnic hypoxia. Forearm vascular resistance (FVR) decreased below baseline during both exposures, reached its highest value above baseline after asphyxia and then declined. After hypocapnic hypoxia FVR rose to baseline after exposure. Hemodynamics are differently altered by hypercapnic relative to hypocapnic 20 min hypoxia, while only hypercapnic hypoxia produces sustained elevation of MSNA during recovery.

Associated Clinical Trials

References

Jun 1, 1971·Respiration Physiology·R S Fitzgerald, D C Parks
Aug 30, 2000·Respiration Physiology·P G Guyenet
Aug 17, 2002·Journal of Applied Physiology·John R Halliwill, Christopher T Minson
Aug 5, 2003·The Journal of Physiology·John R HalliwillNisha Charkoudian

❮ Previous
Next ❯

Citations

Aug 7, 2014·Current Hypertension Reports·Meghna P MansukhaniVirend K Somers
Feb 13, 2010·Journal of Applied Physiology·Jordan S QueridoA William Sheel
May 16, 2009·Current Hypertension Reports·Oded Friedman, Alexander G Logan
May 20, 2006·The Journal of Physiology·Kevin D MonahanChester A Ray
Nov 14, 2006·Experimental Physiology·Michael L Smith, Christina F Pacchia
Nov 25, 2006·Experimental Physiology·Glen E FosterPatrick J Hanly
Oct 4, 2016·Chest·Anna M MayReena Mehra
Feb 20, 2019·Hypertension·Meghna P MansukhaniVirend K Somers
May 2, 2006·American Journal of Physiology. Heart and Circulatory Physiology·Geoffrey GilmartinJ Woodrow Weiss
May 19, 2007·Journal of Applied Physiology·Grant H SimmonsJohn R Halliwill
Sep 18, 2007·American Journal of Physiology. Heart and Circulatory Physiology·Renaud TamisierJ Woodrow Weiss
Feb 26, 2008·American Journal of Physiology. Heart and Circulatory Physiology·Silvia Bertuglia
May 20, 2011·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Keisho KatayamaMitsuru Saito
Apr 12, 2013·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Can Ozan TanJ Andrew Taylor
Mar 21, 2020·Journal of Hypertension·Vinicius P GarciaNatália G Rocha
Oct 1, 2011·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Jordan S QueridoA William Sheel
Oct 12, 2018·Journal of Magnetic Resonance Imaging : JMRI·Tameshwar GaneshHai-Ling Margaret Cheng
Apr 15, 2008·Experimental Biology and Medicine·Tatiana V SerebrovskayaRobert T Mallet
Jul 21, 2012·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Craig D Steinback, J Kevin Shoemaker
Mar 9, 2013·Journal of Applied Physiology·Jordan S QueridoA William Sheel
Dec 19, 2008·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Craig D SteinbackJ Kevin Shoemaker
May 7, 2020·Journal of Hypertension·Vinicius P GarciaNatália G Rocha
Sep 19, 2019·Respiratory Physiology & Neurobiology·Fabian RoderOlaf Oldenburg
Jan 8, 2021·Journal of Applied Physiology·Caitlin P JarrardSophie Lalande
Nov 20, 2020·Journal of Applied Physiology·Shigehiko Ogoh, Damian M Bailey
May 7, 2021·Journal of Applied Physiology·Frank WojanSophie Lalande
Sep 17, 2021·Clinical Autonomic Research : Official Journal of the Clinical Autonomic Research Society·Andrew R SteeleCraig D Steinback
Oct 17, 2021·Experimental Neurology·Andrew E BeaudinMarc J Poulin

❮ Previous
Next ❯

Related Concepts

Related Feeds

Bradyarrhythmias

Bradyarrhythmias are slow heart rates. Symptoms may include syncope, dizziness, fatigure, shortness of breath, and chest pains. Find the latest research on bradyarrhythmias here.

Related Papers

American Journal of Respiratory and Critical Care Medicine
F J NietoJohn A Robbins
American Journal of Respiratory and Critical Care Medicine
Mary S M IpWah-Kit Lam
American Journal of Respiratory and Critical Care Medicine
Silke RyanWalter T McNicholas
© 2022 Meta ULC. All rights reserved