The dopamine-depleting effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in CD-1 mice are gender-dependent.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a selective dopaminergic neurotoxin affecting the nigrostriatal system in a variety of species including, rodents, nonhuman primates and humans. There exists, however, a great deal of variability in the sensitivity of different species to the effects of MPTP. The present study was designed to determine whether a significant difference in gender susceptibility to the toxin in CD-1 mice might also exist. A dosing regiment of 30 mg/kg MPTP once a day for 3 days (90 mg/kg total dose) in 4-month-old male and female CD-1 mice led to a significant depletion of striatal dopamine in both sexes. Two way ANOVA analysis of a time-course generated by measuring striatal dopamine at 4, 12 and 24 h after each dose of MPTP revealed that the initial dopamine reduction is significantly greater in male CD-1 mice (P < 0.001). Further, dopamine levels were reduced to a greater extent in male mice 5 days after the last dose (31% vs. 59% of control; P < 0.02). HPLC analysis using fluorescence detection revealed no difference in the striatal nor the cerebellar levels of MPP+ between the two sexes, however, accumulation of larger amounts of MPP+ was observed in the livers of the female mice. These findings suggest that, while female CD-1 mice are more resistant to the dopamine-depleting effects of MPTP, this gender difference is not due to decreased or accumulation of striatal MPP+.
Freyaldenhoven
T E
TE
Division of Neurotoxicology, National Center for Toxicology Research, Jefferson, AR 72079-9502, USA.
Cadet
J L
JL
Ali
S F
SF
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology*; D015655:1-Methyl-4-phenylpyridinium / Q000378:metabolism; D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D015259:Dopamine Agents / Q000494:pharmacology*; D005260:Female; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012727:Sex Characteristics; D013997:Time Factors
D015259:Dopamine Agents; D015102:3,4-Dihydroxyphenylacetic Acid; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D015655:1-Methyl-4-phenylpyridinium; D004298:Dopamine; D006719:Homovanillic Acid