Document Detail


O2 tension in adult and neonatal brain slices under several experimental conditions.
MedLine Citation:
PMID:  1814564     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Brain tissue O2 tension (pO2) was measured in brainstem slices of adult and neonatal rats using carbon fiber polarographic microelectrodes. These studies were performed in order to examine the relation between pO2 and a variety of experimental conditions including temperature, distance from slice surface, brain region, animal age, tissue thickness and ambient O2 levels. Baseline brain tissue pO2 was inversely proportional to temperature and depth from slice surface. White matter had a much higher pO2 than gray matter. Tissue thickness and animal age had major effects on tissue pO2. In slices of 800 microns thick at 37 degrees C, for example, brain tissue pO2 in the adult dropped to 0 mm Hg at a depth of 200-300 microns, but remained above 45 mm Hg throughout neonatal (3-10 days) slices, when O2 tension in the perfusate was about 600 mm Hg. In thicker neonatal slices (1500 microns), pO2 decreased also to 0 mm Hg in deep areas. An N2 environment produced a rapid reduction in pO2 to 0 mm Hg within 15 s, and O2 levels of 21, 10 and 5% induced graded pO2 minima and graded latencies to reach each pO2 nadir. We conclude that: (1) tissue thickness has a major effect on tissue pO2 level: pO2 can reach zero if the slice is thicker than 600 microns in the adult and 1500 microns thick in the neonate; (2) pO2 level is higher in neonatal brain tissue at all ambient O2 concentrations than in the adult; and (3) graded hypoxia produces patterned and graded reductions in tissue pO2.
Authors:
C Jiang; S Agulian; G G Haddad
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Publication Detail:
Type:  Comparative Study; In Vitro; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Brain research     Volume:  568     ISSN:  0006-8993     ISO Abbreviation:  Brain Res.     Publication Date:  1991 Dec 
Date Detail:
Created Date:  1992-06-23     Completed Date:  1992-06-23     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0045503     Medline TA:  Brain Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  159-64     Citation Subset:  IM    
Affiliation:
Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06510.
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MeSH Terms
Descriptor/Qualifier:
Aging
Animals
Animals, Newborn
Anoxia
Brain / growth & development,  metabolism*
Organ Specificity
Oxygen / analysis,  metabolism*
Partial Pressure
Polarography / methods
Rats
Grant Support
ID/Acronym/Agency:
HD 15736/HD/NICHD NIH HHS; HL 39924/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

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


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