title: Expiration of ethane in rats under variously elevated inspiratory O2-concentrations.
abstract: Expired ethane is regarded as a noninvasive indicator of lipid peroxidation. As a model of oxidative stress we have investigated in male Wistar rats (body wt. 309 +/- 15 g) the effects of various levels of elevated inspiratory oxygen concentrations on the expiration rate of ethane. After 4 days under 21 vol% O2 (basic condition) the rats were exposed for 6 or 5 days to 40, 60 or 80 vol% O2 over 8 or 23 h/day. The variously O2-enriched air was conducted through the cages and expired ethane adsorbed onto charcoal was thermo-desorbed and measured by gas chromatography. Basic ethane expiration was 3.1 +/- 0.8 pmol/100 g body wt. per min. At 40 vol% O2 over 8 or 23 h/day no increase or a maximum average 47% increase (P < 0.01) in ethane expiration occurred on day 4; 60 vol% O2 over 8 or 23 h/day led to a corresponding increase of 56 or 87% (P < 0.05 or P < 0.01) on day 3; 80 vol% O2 over 8 or 23 h/day led to a corresponding increase of 81 or 66% (P < 0.01) on days 3 or 2. Our results indicate that with up to 60 vol% O2 a temporary increase in lipid peroxidation occurs in a dose dependent manner. However, at 80 vol% O2 no further increase in the maximum ethane expiration occurred. The latter finding and the finding of only transient increase in ethane expiration in probably due to antioxidative counteraction.
authors.affiliation: Forschungsinstitut für Kinderernährung, Heinstück 11, Dortmund, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Kritzler
authors.forename: G
authors.initials: G
authors.lastname: Schöch
authors.forename: H
authors.initials: H
authors.lastname: Topp
mesh_terms: D000818:Animals; D001944:Breath Tests; D004980:Ethane / Q000032:analysis*; D008297:Male; D018384:Oxidative Stress; D010100:Oxygen / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D017382:Reactive Oxygen Species; D004980:Ethane; D010100:Oxygen