| Fast bicarbonate-chloride exchange between brain cells and brain extracellular fluid in respiratory acidosis. | |
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MedLine Citation:
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PMID: 7155803 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The extracellular pH, PCO2, and [Cl-] at the surface of the brain cortex, expiratory PCO2 and arterial blood pressure were continuously recorded in anaesthetized and artificially ventilated cats. The observations from such a preparation were: 1. In response to a nearly step increase in end-tidal PCO2, the brain ECF pH, PCO2, [Cl-] and calculated [HCO-3] changed in the form of a nearly mono-exponential time function after a delay of 5-7 s. 2. The time constants of the changes in the extracellular pH, PCO2, [Cl-] and [HCO-3] were in the range of 30-40 s. 3. The extracellular [HCO-3] increased markedly at an initial rate of 4.22 mmol.1(-1) . min-1 after 36 s. 4. This increase occurred almost simultaneously with a decrease in the extracellular [Cl-]. An [HCO-3]-[Cl-] exchange ratio was determined which very closely approached one. It is concluded that the brain extracellular bicarbonate concentration in respiratory acidosis increases because the H+ formed from the hydrated CO2 reacts with the intracellular buffers of brain cells, mainly glial cells, and HCO-3 inside the cell is formed and exchanged for Cl- outside the cell similar to the HCO-3/Cl- exchange which occurs between red cells and blood plasma during CO2 loading. The described time constants of the anion exchange represent the wash in or wash out time of CO2 in a tissue containing intracellular buffer. |
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Authors:
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H R Ahmad; H H Loeschcke |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Pflügers Archiv : European journal of physiology Volume: 395 ISSN: 0031-6768 ISO Abbreviation: Pflugers Arch. Publication Date: 1982 Dec |
Date Detail:
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Created Date: 1983-03-17 Completed Date: 1983-03-17 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0154720 Medline TA: Pflugers Arch Country: GERMANY, WEST |
Other Details:
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Languages: eng Pagination: 293-9 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Acidosis, Respiratory
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metabolism* Animals Bicarbonates / metabolism* Brain / cytology, metabolism* Cats Chlorides / metabolism* Extracellular Space / metabolism* Female Homeostasis Male Time Factors |
| Chemical | |
Reg. No./Substance:
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0/Bicarbonates; 0/Chlorides |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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