Document Detail


Oxygen tension in rat cerebral cortex microvessels in acute anemia.
MedLine Citation:
PMID:  18607751     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Polarigraphic microelectrodes were used to study the distribution of oxygen tension (pO(2)) in arterioles (lumen diameters 8-80 microm) and venules (lumen diameters 8-120 microm) in the rat cerebral cortex during acute reductions in blood hemoglobin ([Hb]). Isovolumic hemodilution with 5% albumin solution was performed in steps from an initial [Hb] of 14.1 +/- 0.3 g/dl (control) to 9.8 +/- 0.3 g/dl (step 1), 6.6 +/- 0.4 g/dl (step 2), and 4.6 +/- 0.3 g/dl (step 3). Mild anemia (step 1, hematocrit 30%) led to an increase in pO(2) in the arterial side of the microcirculatory bed, with virtually no change in pO(2) in the venous side. Step 2 (hematocrit 20%) was accompanied by a further insignificant increase in pO(2) in arterioles, while there was a significant reduction (on average to 32 mmHg) in venules. Step 3 (hematocrit 13-14%) led to a (statistically insignificant) increase in pO(2) in arterioles. pO(2) in venules decreased, on average, to 27 mmHg; the proportion of smallest venules with low pO(2) values (less than 20 mmHg) increased to 31% (from 3% in controls). In some capillaries, pO(2) was 5-10 mmHg, which was an indicator of the presence of hypoxic zones in brain tissues. These zones primarily arose close to the smallest capillary and venous microvessels, with slowed or impaired blood flow.
Authors:
E P Vovenko; A E Chuikin
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-07-08
Journal Detail:
Title:  Neuroscience and behavioral physiology     Volume:  38     ISSN:  0097-0549     ISO Abbreviation:  Neurosci. Behav. Physiol.     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-08-12     Completed Date:  2008-12-09     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0330471     Medline TA:  Neurosci Behav Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  493-500     Citation Subset:  IM    
Affiliation:
Tissue Gas Exchange Physiology Group, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, St. Petersburg, Russia. epv@infran.ru
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MeSH Terms
Descriptor/Qualifier:
Acute Disease
Anemia / blood,  complications,  metabolism*
Animals
Anoxia / blood*,  etiology
Arterioles / metabolism
Cerebral Cortex / blood supply,  metabolism*
Disease Models, Animal
Hemoglobins / deficiency,  metabolism*
Male
Oxygen / blood
Oxygen Consumption / physiology*
Rats
Rats, Wistar
Severity of Illness Index
Venules / metabolism
Chemical
Reg. No./Substance:
0/Hemoglobins; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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