Neuropeptide levels in the basal ganglia of aged common marmosets following prolonged treatment with MPTP.
Aged common marmosets were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 0.5-2.0 mg/kg/week i.p.) for 16 or 24 weeks, observed for a total of 30 weeks and then killed for measurement of biochemical parameters in basal ganglia. The MPTP treatment induced a marked depletion in dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid levels in the caudate nucleus and putamen. In contrast, the concentrations of five neuropeptides: [Met5]-enkephalin, [Leu5]-enkephalin, cholecystokinin, substance P and neurotensin as measured by a combined HPLC/RIA method, remained unaltered in all basal ganglia regions examined. Enkephalin precursor levels, as reflected by cryptic [Met5]-enkephalin content, were increased in the putamen, but not in the caudate nucleus, as a consequence of MPTP administration. Cryptic [Leu5]-enkephalin content remained unchanged in the striatum of MPTP treated marmosets. Overall, these results suggest an increase in striatal [Met5]-enkephalin release following chronic MPTP treatment of aged marmosets. However, the chronic treatment of aged marmosets with MPTP does not reproduce the neuropeptide alterations characteristic of Parkinson's disease.
Taylor
M D
MD
Parkinson's Disease Society Experimental Research Laboratories, Biomedical Sciences Division, King's College, London, United Kingdom.
de Ceballos
M L
ML
Rose
S
S
Chong
P N
PN
Jenner
P
P
Marsden
C D
CD
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology*; D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000375:Aging; D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D015306:Biogenic Monoamines / Q000378:metabolism*; D002144:Callithrix; D002421:Caudate Nucleus / Q000502:physiology; D004298:Dopamine / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000302:isolation & purification / Q000378:metabolism; D004744:Enkephalin, Methionine / Q000302:isolation & purification / Q000378:metabolism; D005260:Female; D005917:Globus Pallidus / Q000502:physiology; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D009479:Neuropeptides / Q000378:metabolism*; D009496:Neurotensin / Q000378:metabolism; D011699:Putamen / Q000502:physiology; D012016:Reference Values; D012844:Sincalide / Q000378:metabolism; D013373:Substance P / Q000378:metabolism
D015306:Biogenic Monoamines; D009479:Neuropeptides; D015102:3,4-Dihydroxyphenylacetic Acid; D013373:Substance P; D009496:Neurotensin; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D012844:Sincalide; D004298:Dopamine; D006719:Homovanillic Acid