Document Detail

Ionic determinants of exhaled breath condensate pH before and after exercise in adolescent athletes.
MedLine Citation:
PMID:  19598280     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: The pH of exhaled breath condensate (EBC) of adolescent athletes engaged in vigorous physical activity is low compared to healthy controls; however, the ionic determinants of EBC pH and the acute effects of exercise on those determinants have not been definitively established. OBJECTIVES: This study had two purposes: (1) to identify the ionic composition of EBC before and after exercise, and (2) to examine the effects of sample deaeration on EBC pH and composition. METHODS: EBC ionic composition was determined by ion chromatography and correlated with pH measured before and after deaeration. Bicarbonate concentration was calculated from the ion balance of other measured species and pH. RESULTS: EBC pH displayed a bimodal distribution, included values lower than expected for healthy individuals, and was correlated exclusively with volatile species, namely ammonia (mean concentration = 215 microM) and acetic (31.7 microM) and propionic acids (10.0 microM). Following exercise, raw EBC pH and ammonia concentration increased while propionic acid concentration fell. Following deaeration, EBC pH increased by one unit on average; however, the pH of samples with unusually low pH did not change significantly, and the concentrations of several ionic species were altered in a manner that cannot be explained in terms of volatility. CONCLUSIONS: We conclude that in healthy adolescents, exercise results in an acute increase in raw EBC pH in association with an increase in ammonium and a decrease in propionate concentration. Since exercise increases systemic ammonia and urea (which is hydrolyzed by oral bacteria to form ammonia), we propose that the likely source of these changes is gas-phase diffusion from epithelial and oral surface liquids and to a lesser extent, from pulmonary circulation.
Roby Greenwald; Jill M Ferdinands; W Gerald Teague
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Pediatric pulmonology     Volume:  44     ISSN:  1099-0496     ISO Abbreviation:  Pediatr. Pulmonol.     Publication Date:  2009 Aug 
Date Detail:
Created Date:  2009-07-28     Completed Date:  2009-10-27     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8510590     Medline TA:  Pediatr Pulmonol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  768-77     Citation Subset:  IM    
Division of Pulmonary, Allergy, Cystic Fibrosis, and Sleep Medicine, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Acetic Acid / analysis
Ammonia / analysis
Breath Tests*
Carbon Dioxide / analysis
Carbonates / analysis
Chromatography, Ion Exchange
Hydrogen-Ion Concentration
Ions / analysis
Propionates / analysis
Grant Support
Reg. No./Substance:
0/Carbonates; 0/Ions; 0/Propionates; 124-38-9/Carbon Dioxide; 64-19-7/Acetic Acid; 7664-41-7/Ammonia

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

Previous Document:  Overexpression of Zip-2 mRNA in the leukocytes of asthmatic infants.
Next Document:  The effects of racemic albuterol versus levalbuterol in very low birth weight infants.