TY - JOUR
T1 - Morphological and biochemical evidence that apomorphine rescues striatal dopamine terminals and prevents methamphetamine toxicity
AU - Battaglia, G.
AU - Gesi, M.
AU - Lenzi, P.
AU - Busceti, C. L.
AU - Soldani, P.
AU - Orzi, F.
AU - Rampello, L.
AU - Nicoletti, F.
AU - Ruggieri, S.
AU - Fornai, F.
PY - 2002
Y1 - 2002
N2 - Apomorphine, given by a single injection, repeated injections, or by continuous infusion, was tested for neuroprotective effects in mice administered methamphetamine or N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in order to induce striatal dopamine (DA) depletion. In the first part of the study, the DA agonist (R)-apomorphine was administered at various doses (1, 5, and 10 mg/kg), 15 min before methamphetamine (5 mg/kg × 3, 2 h apart). Mice were sacrificed 5 days later. In the second part, apomorphine was administered either continuously by subcutaneous minipump (cumulative daily dose of 0.5, 1, and 3.15 mg/kg), or as single, repeated daily injections (up to 5 mg/kg) starting 40 h after an acute administration of MPTP (30 mg/kg). Mice were sacrificed at different time intervals (up to 1 month) following MPTP injection. In all the animals, the integrity of striatal DA terminals was evaluated by measuring striatal DA levels and TH immunohistochemistry. Apomorphine dose-dependently prevented methamphetamine toxicity. These effects were neither due to a decrease in the amount of striatal methamphetamine nor to the hypothermia, and they were not reversed by the DA antagonist haloperidol. Moreover, chronic, continuous (but not pulsatile) administration of apomorphine rescued damaged striatal dopaminergic terminals. These findings confirm a protective effect of apomorphine that also consists of a neurorescue of damaged striatal DA terminals. This suggests a new hypothesis about the long-term benefits observed during continuous apomorphine administration in Parkinson's disease patients.
AB - Apomorphine, given by a single injection, repeated injections, or by continuous infusion, was tested for neuroprotective effects in mice administered methamphetamine or N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in order to induce striatal dopamine (DA) depletion. In the first part of the study, the DA agonist (R)-apomorphine was administered at various doses (1, 5, and 10 mg/kg), 15 min before methamphetamine (5 mg/kg × 3, 2 h apart). Mice were sacrificed 5 days later. In the second part, apomorphine was administered either continuously by subcutaneous minipump (cumulative daily dose of 0.5, 1, and 3.15 mg/kg), or as single, repeated daily injections (up to 5 mg/kg) starting 40 h after an acute administration of MPTP (30 mg/kg). Mice were sacrificed at different time intervals (up to 1 month) following MPTP injection. In all the animals, the integrity of striatal DA terminals was evaluated by measuring striatal DA levels and TH immunohistochemistry. Apomorphine dose-dependently prevented methamphetamine toxicity. These effects were neither due to a decrease in the amount of striatal methamphetamine nor to the hypothermia, and they were not reversed by the DA antagonist haloperidol. Moreover, chronic, continuous (but not pulsatile) administration of apomorphine rescued damaged striatal dopaminergic terminals. These findings confirm a protective effect of apomorphine that also consists of a neurorescue of damaged striatal DA terminals. This suggests a new hypothesis about the long-term benefits observed during continuous apomorphine administration in Parkinson's disease patients.
KW - Apomorphine
KW - Dopaminergic neurons
KW - Methamphetamine
KW - MPTP
KW - Neuroprotection
KW - Neurorescue
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M3 - Article
C2 - 12105101
AN - SCOPUS:0036296950
VL - 965
SP - 254
EP - 266
JO - Annals of the New York Academy of Sciences
JF - Annals of the New York Academy of Sciences
SN - 0077-8923
ER -