|
|
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Pharmacology and Toxicology, Virginia Commonwealth University Medical Center, Richmond, Virginia (M.I.D., S.M., B.R.M.); Research Triangle Institute, Research Triangle Park, North Carolina (F.I.C., H.A.N., B.E.B.); and Barrow Neurological Institute, Division of Neurobiology, Phoenix Arizona (J.B.E., R.J.L.)
Bupropion is an atypical antidepressant that also has usefulness as a smoking-cessation aid. Because hydroxybupropion, a major metabolite of bupropion, is believed to contribute to its antidepressant activity, this metabolite may also contribute to the smoking-cessation properties of bupropion. This study investigated the effects of hydrobupropion enantiomers on monoamine transporters and nicotinic acetylcholine receptor (nAChR) subtypes. Racemic bupropion and hydroxybupropion inhibit [3H]norepinephrine (NE) uptake with similar potency (IC50 values of 1.9 and 1.7 µM, respectively), but most of the latter activity resides in the (2S,3S)-hydroxy isomer (IC50 = 520 nM) rather than (2S,3R)-hydroxybupropion (IC50 > 10,000 nM). Similar results were found with [3H]dopamine (DA) uptake. The effects of bupropion and enantiomers of hydroxybupropion on human nAChR subtypes indicate that the (2S,3S) isomer is more potent than the (2S,3R) isomer or racemic bupropion as an antagonist of
4
2 (functional IC50 = 3.3 µM). In addition, (2S,3S)-hyroxybupropion and bupropion were considerably more potent than (2R, 3R)-hydroxybupropion in a mouse depression model (forced swimming test) and in antagonism of acute nicotine effects in mice. Together, our results suggest that clinical and behavioral effects of bupropion arise from actions at nAChR as well as DA and NE transporters. Furthermore, our data suggest that the (2S,3S)-hydroxybupropion isomer may be a better drug candidate for smoking cessation than bupropion because of its higher potency at the relevant targets.
Address correspondence to: Dr. M. Imad Damaj, Department of Pharmacology and Toxicology, Virginia Commonwealth University, 12th North and Clay Streets, Smith Building, Box 980613, Richmond, VA 23298-0613. E-mail: mdamaj{at}hsc.vcu.edu
This article has been cited by other articles:
![]() |
S. W. Smith Chiral Toxicology: It's the Same Thing...Only Different Toxicol. Sci., July 1, 2009; 110(1): 4 - 30. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. O. Ebbert, I. T. Croghan, A. Sood, D. R. Schroeder, J. T. Hays, and R. D. Hurt Varenicline and bupropion sustained-release combination therapy for smoking cessation Nicotine Tob Res, March 1, 2009; 11(3): 234 - 239. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. R. Uhl, Q.-R. Liu, T. Drgon, C. Johnson, D. Walther, J. E. Rose, S. P. David, R. Niaura, and C. Lerman Molecular Genetics of Successful Smoking Cessation: Convergent Genome-Wide Association Study Results Arch Gen Psychiatry, June 1, 2008; 65(6): 683 - 693. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. D. Kharasch, D. Mitchell, and R. Coles Stereoselective Bupropion Hydroxylation as an In Vivo Phenotypic Probe for Cytochrome P4502B6 (CYP2B6) Activity J. Clin. Pharmacol., April 1, 2008; 48(4): 464 - 474. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Lee and R. F. Tyndale Drugs and genotypes: how pharmacogenetic information could improve smoking cessation treatment J Psychopharmacol, July 1, 2006; 20(4_suppl): 7 - 14. [Abstract] [PDF] |
||||
![]() |
L. M. Hesse, D. J. Greenblatt, L. L. von Moltke, and M. H. Court Ritonavir has minimal impact on the pharmacokinetic disposition of a single dose of bupropion administered to human volunteers. J. Clin. Pharmacol., May 1, 2006; 46(5): 567 - 576. [Abstract] [Full Text] [PDF] |
||||