| 12388632 |
Unger EL, Mazzola-Pomietto P, Murphy DL, Andrews AM: 2'-NH (2)-MPTP [1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine] depletes serotonin and norepinephrine in rats: a comparison with 2'-CH (3)-MPTP [1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine]. J Pharmacol Exp Ther. 2002 Nov;303(2):527-33.
The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) analog, 1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine (2'-NH (2)-MPTP), depletes brain serotonin and norepinephrine in mice without affecting striatal dopamine. The present study was conducted to determine whether 2'-NH (2)-MPTP would be similarly neurotoxic to rats. Four injections of 20 mg/kg 2'-NH (2)-MPTP caused 80 to 90% depletions in serotonin and norepinephrine in frontal cortex and hippocampus in rats 1 week post-treatment. A lower dose of 2'-NH (2)-MPTP (4 x 15 mg/kg) also produced large decrements in serotonin and norepinephrine levels and in serotonin transporter density measured 3 weeks after neurotoxin administration. Furthermore, this lower dose of 2'-NH (2)-MPTP altered functional serotonin neurotransmission as evidenced by a 2-fold potentiation of 1-(3-chlorophenyl)-piperazine.2HCl-induced hyperthermia, an index of serotonergic denervation supersensitivity. At both doses, 2'-NH (2)-MPTP was without effect on striatal dopamine. For comparison, additional rats were treated with a second 2'-substituted analog of MPTP, 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH (3)-MPTP), at 2 x 20 mg/kg. This dosing regimen causes substantial striatal dopamine depletion in mice. 2'-CH (3)-MPTP had no effect on brain levels of serotonin, norepinephrine, or dopamine in rats. Together, these results demonstrate that rats are sensitive to the toxic effects of 2'-NH (2)-MPTP but not to 2'-CH (3)-MPTP at doses known to cause neurotoxicity in mice. Moreover, this study clearly shows that 2'-NH (2)-MPTP can be utilized in rats as a tool to study the serotonergic and noradrenergic neurotransmitter systems. |
1(0,0,0,1) |