Increase of striatal dopamine turnover by stress in MPTP-treated mice.
The characteristics of motor function and brain dopamine (DA) metabolism in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice after immersion immobilization stress were investigated. There was no significant difference in locomotor activities between MPTP-treated and saline-treated mice, but locomotor activities of MPTP-treated mice after stress decreased more remarkably than those of saline-treated mice. Immediately after stress, striatal DA concentrations of MPTP-treated mice were significantly lower than those of saline-treated mice. Striatal DA levels improved when 24 h passed after stress. The striatal and cortical (DOPAC + HVA)/DA ratios of MPTP-and stress-treated mice was significantly higher than that of saline-and stress-treated mice. It is due to the decreased DA level and the enhancement of DA turnover that MPTP-treated mice became remarkably akinetic after stress, and that L-DOPA therapy is not effective when the symptoms in patients with Parkinson's disease worsen due to stress.
Urakami
K
K
Division of Neurology, Tottori University School of Medicine, Yonago, Japan.
Masaki
N
N
Shimoda
K
K
Nishikawa
S
S
Takahashi
K
K
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology*; D012016:Reference Values; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000503:physiopathology*
D011725:Pyridines; D015102:3,4-Dihydroxyphenylacetic Acid; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D004298:Dopamine; D006719:Homovanillic Acid