Document Detail


Effect of oxygen breathing on micro oxygen bubbles in nitrogen-depleted rat adipose tissue at sea level and 25 kPa altitude exposures.
MedLine Citation:
PMID:  22653987     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The standard treatment of altitude decompression sickness (aDCS) caused by nitrogen bubble formation is oxygen breathing and recompression. However, micro air bubbles (containing 79% nitrogen), injected into adipose tissue, grow and stabilize at 25 kPa regardless of continued oxygen breathing and the tissue nitrogen pressure. To quantify the contribution of oxygen to bubble growth at altitude, micro oxygen bubbles (containing 0% nitrogen) were injected into the adipose tissue of rats depleted from nitrogen by means of preoxygenation (fraction of inspired oxygen = 1.0; 100%) and the bubbles studied at 101.3 kPa (sea level) or at 25 kPa altitude exposures during continued oxygen breathing. In keeping with previous observations and bubble kinetic models, we hypothesize that oxygen breathing may contribute to oxygen bubble growth at altitude. Anesthetized rats were exposed to 3 h of oxygen prebreathing at 101.3 kPa (sea level). Micro oxygen bubbles of 500-800 nl were then injected into the exposed abdominal adipose tissue. The oxygen bubbles were studied for up to 3.5 h during continued oxygen breathing at either 101.3 or 25 kPa ambient pressures. At 101.3 kPa, all bubbles shrank consistently until they disappeared from view at a net disappearance rate (0.02 mm(2) × min(-1)) significantly faster than for similar bubbles at 25 kPa altitude (0.01 mm(2) × min(-1)). At 25 kPa, most bubbles initially grew for 2-40 min, after which they shrank and disappeared. Four bubbles did not disappear while at 25 kPa. The results support bubble kinetic models based on Fick's first law of diffusion, Boyles law, and the oxygen window effect, predicting that oxygen contributes more to bubble volume and growth during hypobaric conditions. As the effect of oxygen increases, the lower the ambient pressure. The results indicate that recompression is instrumental in the treatment of aDCS.
Authors:
Thomas Randsoe; Ole Hyldegaard
Related Documents :
8679347 - Cricoid pressure applied after placement of the laryngeal mask prevents gastric insuffl...
24889627 - Pressure-enabled phonon engineering in metals.
4686467 - Haptic illusion: apparent elongation of a disk rotated between the fingers.
18145967 - Crossed leg palsy; with report of a recurrent case.
3145337 - Improved heart preservation with uw preservation solution.
18040067 - Nitrosyl-cobinamide, a new and direct nitric oxide releasing drug effective in vivo.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-05-31
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  113     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2012 Aug 
Date Detail:
Created Date:  2012-08-02     Completed Date:  2013-01-08     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  426-33     Citation Subset:  IM    
Affiliation:
Laboratory of Hyperbaric Medicine, Department of Anesthesia, Centre of Head and Orthopedics, Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adipose Tissue / drug effects*
Altitude Sickness / therapy*
Animals
Decompression Sickness / therapy*
Diffusion
Female
Oxygen / administration & dosage*
Rats
Rats, Wistar
Respiration*
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

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


Previous Document:  WISE 2005: responses of women to sublingual nitroglycerin before and after 56 days of 6° head-down ...
Next Document:  Coenzyme Q10 reverses mitochondrial dysfunction in atorvastatin-treated mice and increases exercise ...