Role of dopamine transporter in methamphetamine-induced neurotoxicity: evidence from mice lacking the transporter.
The role of the dopamine transporter (DAT) in mediating the neurotoxic effects of methamphetamine (METH) was tested in mice lacking DAT. Dopamine (DA) and serotonin (5-HT) content, glial fibrillary acidic protein (GFAP) expression, and free radical formation were assessed as markers of METH neurotoxicity in the striatum and/or hippocampus of wild-type, heterozygote, and homozygote (DAT -/-) mice. Four injections of METH (15 mg/kg, s.c.), each given 2 hr apart, produced 80 and 30% decreases in striatal DA and 5-HT levels, respectively, in wild-type animals 2 d after administration. In addition, GFAP mRNA and protein expression levels, extracellular DA levels, and free radical formation were increased markedly. Hippocampal 5-HT content was decreased significantly as well (43%). Conversely, no significant changes were observed in total DA content, GFAP expression, extracellular DA levels, or free radical formation in the striatum of DAT -/- mice after METH administration. However, modest decreases were observed in striatal and hippocampal 5-HT levels (10 and 17%, respectively). These observations demonstrate that DAT is required for, and DA is an essential mediator of, METH-induced striatal dopaminergic neurotoxicity, whereas serotonergic deficits are only partially dependent on DAT.
Fumagalli
F
F
Howard Hughes Medical Institute Laboratories, Department of Cell Biology and Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
Gainetdinov
R R
RR
Valenzano
K J
KJ
Caron
M G
MG
D000818:Animals; D015415:Biomarkers; D001831:Body Temperature / Q000187:drug effects; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D003342:Corpus Striatum / Q000737:chemistry / Q000378:metabolism; D004298:Dopamine / Q000032:analysis / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors / Q000633:toxicity*; D015870:Gene Expression / Q000502:physiology; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008694:Methamphetamine / Q000633:toxicity*; D051379:Mice; D018345:Mice, Knockout / Q000502:physiology*; D017551:Microdialysis; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D009498:Neurotoxins / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012701:Serotonin / Q000032:analysis / Q000378:metabolism
D015415:Biomarkers; D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D018765:Dopamine Uptake Inhibitors; D005904:Glial Fibrillary Acidic Protein; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D009498:Neurotoxins; D017382:Reactive Oxygen Species; C493215:Slc6a3 protein, mouse; D012701:Serotonin; D008694:Methamphetamine; D004298:Dopamine