Effects of (+/-)-idazoxan alone and in combination with L-DOPA methyl ester in MPTP-induced hemiparkinsonian monkeys.
The effects of a combination of the alpha2-adrenergic receptor antagonist (+/-)-idazoxan with L-DOPA methyl ester were examined in three of four female adult monkeys (Macaca nemestrina) rendered hemiparkinsonian with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). (+/-)-Idazoxan (0.16, 0.63, and 1.0 mg/kg) was given i.m. 10 min before L-DOPA methyl ester (12.5 mg/kg). (+/-)-Idazoxan reduced the maximum peak of contralateral circling elicited during the first hour following injection of L-DOPA methyl ester, but prolonged the duration of the circling response up to 50% (p < 0.05). The data support a role for alpha2-adrenergic receptor mechanisms in modulating the effects of L-DOPA on nigrostriatal dopamine function in the MPTP monkey model of hemiparkinsonism.
Domino
Edward F
EF
Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109-0632, USA. efdabcde@umich.edu
Ni
Lisong
L
Colpaert
Francis
F
Marien
Marc
M
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D000978:Antiparkinson Agents / Q000494:pharmacology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D019329:Idazoxan / Q000494:pharmacology*; D007980:Levodopa / Q000031:analogs & derivatives* / Q000494:pharmacology*; D008254:Macaca nemestrina; D010302:Parkinson Disease, Secondary / Q000188:drug therapy*; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists; D000978:Antiparkinson Agents; D007980:Levodopa; C035420:levodopa methyl ester; D019329:Idazoxan