title: Determination of toluene in brain of freely moving mice using solid-phase microextraction technique.
abstract: For the purpose of measuring the pharmacokinetics of inhaled toluene in the brain of mice, we developed a method for the direct detection of toluene by gas chromatography/mass spectrometry (GC/MS). The method uses a solid-phase microextraction (SPME) fiber inserted into the mouse' hippocampus (CA1) through a cannula fixed onto the animal. BALB/c mice were exposed to 0, 0.9, 9, 50 and 90 ppm toluene for 30 min. The toluene level detected near the hippocampus by this method after exposure to 0.9 ppm toluene in air showed no significant difference from the level found in the non-exposure control group; however, the toluene level increased significantly after exposure to concentrations of 9, 50 and 90 ppm. These increases were concentration-dependent. In addition, the pharmacokinetics of toluene in the brain of mice exposed to 50 ppm toluene showed that the toluene level decreased rapidly after the exposure, and returned to control levels after 60 min. This study describes the method which has successfully detected toluene levels in the brain of conscious, free-moving mice for the first time.
authors.affiliation: Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. dnakajima@nies.go.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nakajima
authors.lastname: Tin-Tin-Win-Shwe
authors.forename: Masaki
authors.initials: M
authors.lastname: Kakeyama
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Fujimaki
authors.forename: Sumio
authors.initials: S
authors.lastname: Goto
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D004305:Dose-Response Relationship, Drug; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D012997:Solvents / Q000032:analysis / Q000493:pharmacokinetics*; D013997:Time Factors; D014050:Toluene / Q000032:analysis / Q000493:pharmacokinetics*; D014851:Wakefulness
chemical_list: D012997:Solvents; D014050:Toluene