title: Regional distribution of tetrahydroisoquinoline derivatives in rodent, human, and Parkinson's disease brain.
abstract: Several members of the tetrahydroisoquinoline (TIQ) family of monoamine alkaloids can be formed from dopamine or its oxidized metabolites and may be involved in the pathogenesis of monoaminergic cell death in Parkinson's disease (PD). Using enantiomeric-selective high-performance liquid chromatography with electrochemical detection and liquid chromatography with tandem mass spectroscopy, the regional concentrations of several TIQ derivatives, including salsolinols, were determined in mouse, rat, normal human, and PD brain. TIQ derivatives were detected in all regions subjected to analysis. In general, salsolinols were present at higher concentrations than TIQ and its benzyl and methyl derivatives, especially in human brain. Moreover, salsolinols were concentrated in areas with increased dopamine synthesis and turnover such as the ventral midbrain and striatum, respectively. A possible consequence of nigrostriatal dopaminergic cell death, significantly lower levels of (R)salsolinol, (S)salsolinol, N-methyl-(R)salsolinol and N-methyl-(S)salsolinol were found in the caudate nuclei of PD in comparison with normal human brain. Our data support the hypothesis of endogenous synthesis of salsolinols and provide evidence for their accumulation in catecholaminergic neurons.
authors.affiliation: Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: DeCuypere
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.forename: Duane D
authors.initials: DD
authors.lastname: Miller
authors.forename: Mark S
authors.initials: MS
authors.lastname: LeDoux
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods; D004298:Dopamine / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D010300:Parkinson Disease / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D053719:Tandem Mass Spectrometry / Q000379:methods; D044005:Tetrahydroisoquinolines / Q000378:metabolism*
chemical_list: D044005:Tetrahydroisoquinolines; D004298:Dopamine