title: [Transportation of the enantiomers of trans tramadol and O-demethyltramadol across blood-brain barrier].
abstract: OBJECTIVE
  To investigate the transportation of the enantiomers of trans tramadol (trans T) and its active metabolite, O-demethyltramadol (M1) across blood-brain barrier.
  
  
  METHODS
  Rats were sacrificed by femoral artery bleeding 1 h after i.p. administration of trans T hydrochloride, 16.7 mg.kg-1 or 50.0 mg.kg-1. Blood, cerebrospinal fluid and cerebral cortex were taken out. The enantiomers of trans T and M1 were analyzed by high performance capillary electrophoresis (HPCE).
  
  
  RESULTS
  Among the three tissues, the concentration of each enantiomer of trans T and M1 was the highest in the cerebral cortex, and the lowest in the cerebrospinal fluid. In the serum, the concentration of (+)-trans T was higher than that of (-)-trans T, and the concentrations of the enantiomers of M1 were similar. In the cerebrospinal fluid and cerebral cortex, the concentration of (+)-trans T was higher than that of (-)-trans T, and the concentrations of (+)-M1 was lower than that of (-)-M1.
  
  
  CONCLUSIONS
  The transportation across blood-brain barrier of the enantiomers of trans T and M1 was stereoselective. In the brain tissues, the concentrations of (+)-trans T and (-)-M1 were higher than those of their enantiomers.
authors.affiliation: Department of Clinical Pharmacology, Bethune International Peace Hospital, Shijiazhuang 050082, China. lhcl@sj-user.he.cninfo.net
authors.forename: H C
authors.initials: HC
authors.lastname: Liu
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Hu
authors.forename: J F
authors.initials: JF
authors.lastname: Liu
authors.forename: N
authors.initials: N
authors.lastname: Wang
authors.forename: Y N
authors.initials: YN
authors.lastname: Hou
mesh_terms: D000701:Analgesics, Opioid / Q000097:blood / Q000493:pharmacokinetics*; D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D002555:Cerebrospinal Fluid / Q000378:metabolism; D005260:Female; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism; D014147:Tramadol / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000701:Analgesics, Opioid; C080580:O-demethyltramadol; D014147:Tramadol