AJP - Regu Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol 281: R528-R538, 2001;
0363-6119/01 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (14)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wilson, R. J. A.
Right arrow Articles by Paton, J. F. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wilson, R. J. A.
Right arrow Articles by Paton, J. F. R.
Vol. 281, Issue 2, R528-R538, August 2001

Brain stem PO2 and pH of the working heart-brain stem preparation during vascular perfusion with aqueous medium

R. J. A. Wilson1, J. E. Remmers1, and J. F. R. Paton2

1 Department of Medical Physiology and Biophysics, Heritage Medical Research Building, University of Calgary, Calgary, Alberta, Canada; and 2 Department of Physiology, University of Bristol, Bristol BS8 1TD, United Kingdom

The rat working heart-brain stem preparation (WHBP) is an in situ preparation having many of the advantages associated with in vitro preparations while retaining cardiovascular response functionality and an eupnoeic respiratory motor pattern. The preparation is perfused arterially with an aqueous medium having a much lower oxygen-carrying capacity than blood. To evaluate the efficacy of the artificial perfusion in providing adequate gas exchange within the brain stem, we used polarographic PO2 and pH microelectrodes to determine the tissue PO2 and pH of the medulla oblongata at various depths. When the perfusate was equilibrated with 5% CO2 and 95% O2, average tissue PO2 was 294 Torr and no hypoxic areas were encountered. Tissue pH was remarkably uniform throughout the tissue, and on average was only 0.04 ± 0.02 pH units more acidic than that of the perfusate. Increasing the PCO2 of the perfusate increased tissue PO2 and decreased arterial resistance. Decreasing perfusate PCO2 (while keeping pH constant) decreased tissue PO2 and reduced the respiratory activity. These results suggest that arterial PCO2, independent of arterial pH, is an essential variable in determining both respiratory drive and cerebrovascular perfusion. We conclude that the medulla of the WHBP is oxygenated and within a physiological pH, which accounts for the eupneic pattern of respiratory motor activity it generates. Furthermore, this preparation may be a useful model for exploring mechanisms of central chemoreception as well as the dynamics of the cerebral vasculature responses following changes in blood gases.

cardiovascular; respiration; breathing; eupnea


This article has been cited by other articles:


Home page
 J. Physiol.Home page
A. Tadjalli, J. Duffin, Y. M. Li, H. Hong, and J. Peever
Inspiratory activation is not required for episodic hypoxia-induced respiratory long-term facilitation in postnatal rats
J. Physiol., December 1, 2007; 585(2): 593 - 606.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
T. A. Day and R. J. A. Wilson
Brainstem PCO2 modulates phrenic responses to specific carotid body hypoxia in an in situ dual perfused rat preparation
J. Physiol., February 1, 2007; 578(3): 843 - 857.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Crit. Care Med.Home page
J. Ren, B. Y. Poon, Y. Tang, G. D. Funk, and J. J. Greer
Ampakines Alleviate Respiratory Depression in Rats
Am. J. Respir. Crit. Care Med., December 15, 2006; 174(12): 1384 - 1391.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
M. B. Harris and W. M. St.-John
Phasic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation
Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R450 - R455.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
T. A. Day and R. J. A. Wilson
Specific carotid body chemostimulation is sufficient to elicit phrenic poststimulus frequency decline in a novel in situ dual-perfused rat preparation
Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R532 - R544.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
J. B. Dean, D. K. Mulkey, A. J. Garcia III, R. W. Putnam, and R. A. Henderson III
Neuronal sensitivity to hyperoxia, hypercapnia, and inert gases at hyperbaric pressures
J Appl Physiol, September 1, 2003; 95(3): 883 - 909.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
M. B. Harris and W. M. St.-John
Tonic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation
Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2003; 285(1): R215 - R221.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
I. C. Solomon, K. H. Chon, and M. N. Rodriguez
Blockade of Brain Stem Gap Junctions Increases Phrenic Burst Frequency and Reduces Phrenic Burst Synchronization in Adult Rat
J Neurophysiol, January 1, 2003; 89(1): 135 - 149.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online