title: Localization of 14C-labeled 2% lidocaine hydrochloride after intraosseous anesthesia in the rabbit.
abstract: OBJECTIVE
  The purpose of this study was to investigate the tissue distribution of lidocaine hydrochloride in mandibular bone marrow after intraosseous anesthesia (IOA) in rabbits.
  
  
  METHODS
  We used macroautoradiography to examine the tissue distribution of a (14)C-labeled 2% lidocaine hydrochloride solution containing 1:80,000 epinephrine ((14)C-lidocaine). Under general anesthesia, (14)C-lidocaine was injected intraosseously or paraperiosteally. After IOA, animals were divided into three groups and observed at 1 (IOA-1), 5 (IOA-5), and 10 minutes (IOA-10) after injection. After infiltration anesthesia (IA), animals were observed at 1 minute after injection.
  
  
  RESULTS
  The accumulation of (14)C-lidocaine was observed around the injection site in both the IA and the IOA groups. Paraperiosteally injected (14)C-lidocaine diffused to the surrounding tissues such as the lip, whereas IOA showed concentrated accumulation around the root apex throughout the experiment. The distribution area was significantly smaller in the IOA-1 group than in the IA group. The distribution area in the IOA-5 group was larger than those in the IOA-1 and IOA-10 groups.
  
  
  CONCLUSIONS
  The accumulation of (14)C-lidocaine injected by IOA in rabbits was concentrated around the root apex. These results may explain the rapid onset time of IOA.
authors.affiliation: Department of Dental Anesthesiology, Tokyo Dental College, Chiba-shi, Japan. gotoutakashi@tdc.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Goto
authors.forename: Hideki
authors.initials: H
authors.lastname: Mamiya
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ichinohe
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Kaneko
mesh_terms: D000766:Anesthesia, Dental / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D001345:Autoradiography; D001853:Bone Marrow / Q000378:metabolism*; D002250:Carbon Radioisotopes / Q000378:metabolism; D007267:Injections; D008012:Lidocaine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D008334:Mandible / Q000378:metabolism; D011817:Rabbits; D014018:Tissue Distribution; D019227:Tooth Apex / Q000378:metabolism
chemical_list: D000779:Anesthetics, Local; D002250:Carbon Radioisotopes; D008012:Lidocaine