| Catechol changes in the rat rostral ventrolateral medulla following changes in systemic CO2. | |
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MedLine Citation:
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PMID: 9321872 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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A catechol signal recorded with in vivo voltammetry within the rat rostral ventrolateral medulla (RVLM) was taken as an index of the activity of RVLM adrenergic neurons and related to the level of arterial PCO2, under halothane anesthesia. Reversible increases in catechol signal were observed during reversible increases in arterial partial CO2 pressure (PaCO2) from 20 to 60 mmHg after alteration of tidal volume (n = 5 intact rats, n = 5 after carotid sinus deafferentation). A reversible increase in inspiratory CO2 combined with constant tidal volume led to changes in PaCO2 from 40 mmHg to 50 or 60 or 70 mmHg for 60 min (n = 5 in each group) and to a reversible increase in catechol signal (r = 0.76). These changes were also observed after carotid sinus deafferentation (PaCO2 = 40 to 60 to 40 mmHg, n = 5). Lowering the PaCO2 from 40 to 20 mmHg led to a minor, nonsignificant reduction in catechol signal (n = 5). Changes in arterial pressure were minimal, although they reached statistical significance in some groups of experiments. The level of catechol metabolism in the RVLM 1) is continuously related to the level of arterial CO2, 2) functions close to its resting level under baseline nonstimulated condition with respect to CO2, and 3) is reversibly modified on changes in capnia. Sensitivity of the catechol signal, recorded in the rostral ventrolateral medulla, to CO2 appears primarily to be centrally mediated. Thus adrenergic RVLM neurons may relay inputs from the central respiratory generator to the sympathetic chemoreflex or act as chemosensors for CO2, next to the ventrolateral medulla surface. |
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Authors:
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N Rentero; N Bruandet; J M Pequignot; L Quintin |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: The American journal of physiology Volume: 273 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1997 Sep |
Date Detail:
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Created Date: 1997-10-23 Completed Date: 1997-10-23 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: R947-55 Citation Subset: IM |
Affiliation:
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School of Medicine, Lyon, France. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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3,4-Dihydroxyphenylacetic Acid
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metabolism* Analysis of Variance Animals Blood Pressure Carbon Dioxide / blood* Carotid Sinus / physiology Denervation Dopamine / metabolism* Heart Rate Hydrogen-Ion Concentration Inhalation Male Medulla Oblongata / physiology* Models, Biological Neurons / physiology* Oxidation-Reduction Oxygen / blood Partial Pressure Rats Rats, Sprague-Dawley Signal Transduction Tidal Volume |
| Chemical | |
Reg. No./Substance:
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102-32-9/3,4-Dihydroxyphenylacetic Acid; 124-38-9/Carbon Dioxide; 7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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