title: Dynamic monitoring of total-body absorption by 19F NMR spectroscopy: one hour ventilation of HFA-134a in male and female rats.
abstract: Six male and six female Sprague-Dawley rats were ventilated head-only for 1 h on a 15% atmosphere of 1,1,1,2-tetrafluoroethane (HFA-134a) in air in a magnetic resonance imaging spectrometer. Results from these dynamic 19F NMR studies suggest that a steady-state in vivo concentration of HFA-134a was approached at approximately 25 min into the exposure. Quantitative integration analysis using an external standard estimated this plateau to be 58.3 +/- 11.9 mg of absorbed HFA-134a per rat. The HFA-134a 19F NMR signal disappeared rapidly following removal of the test atmosphere, with an elimination half-life of 4.6 +/- 0.6 min in the male rats and 4.9 +/- 1.5 min in the female rats. The data suggest that there was no statistical difference between the sexes in amount absorbed or in elimination half-lives.
authors.affiliation: Division of Medicinal Chemistry and Pharmaceutics, College of Pharmacy, University of Kentucky, Lexington 40536-0082, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Finch
authors.forename: E J
authors.initials: EJ
authors.lastname: Dadey
authors.forename: S L
authors.initials: SL
authors.lastname: Smith
authors.forename: L I
authors.initials: LI
authors.lastname: Harrison
authors.forename: G A
authors.initials: GA
authors.lastname: Digenis
mesh_terms: D000042:Absorption; D000280:Administration, Inhalation; D000818:Animals; D002849:Chromatography, Gas; D005260:Female; D005461:Fluorine / Q000493:pharmacokinetics; D005462:Fluorine Radioisotopes; D006207:Half-Life; D006845:Hydrocarbons, Fluorinated / Q000008:administration & dosage / Q000493:pharmacokinetics*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008991:Monitoring, Physiologic; D051381:Rats; D017207:Rats, Sprague-Dawley; D012044:Regression Analysis; D012737:Sex Factors; D014018:Tissue Distribution; D004980:Ethane / Q000031:analogs & derivatives; D005466:Fluorocarbons
chemical_list: D005461:Fluorine; D005462:Fluorine Radioisotopes; D006845:Hydrocarbons, Fluorinated; C063006:norflurane; D004980:Ethane; D005466:Fluorocarbons