Ethene (ethylene) and ethane exhalation in Ni[II]-treated rats, using an improved rebreathing apparatus

To assess the effects of NiCl2 on lipid peroxidation, exhalation rates of ethene (ethylene) and ethane were measured in Fischer-344 rats, using modifications of a recently published rebreathing apparatus and gas chromatographic assay. Technical improvements included more efficient removal of H2O vapor, NH3, and CO2, use of economical, readily available components, convenient standardization procedure, and no necessity for a charcoal concentrator accessory for the gas chromatograph. The detection limit was one pmol ethene or ethane per five mL air sample; the within-run precision (CV) of analysis was 2.1 percent at an ethane concentration of 16 pmol per five mL sample. A minimum of eight hours post-injection was necessary for exhalation rates of ethene or ethane to become significantly increased in NiCl2-treated rats. Ethene exhalation rate was increased 2.0- to 3.5-fold at 13 to 16 and 20 to 23 hours after NiCl2 injection (0.50 or 0.75 mmol per kg, body wt, sc). Ethane exhalation rate was increased 1.5- to 1.6-fold at the lower dosage, but was not significantly increased at the higher dosage of NiCl2. This study corroborates previous reports that lipid peroxidation is enhanced in target tissues (liver, kidney, lung) of NiCl2-treated rats.