title: Pramipexole reduces parkinsonian tremor induced by pilocarpine infusion in the rat striatum.
abstract: OBJECTIVE
  Pramipexole is widely prescribed for the treatment of Parkinson's disease. This dopamine (DA) receptor agonist has a higher affinity for D3 over D2 receptors. We compared the effect of pramipexole to apomorphine, a non-specific DA receptor agonist, on the suppression of tremulous jaw movements (TJMs) in a rat model, to elucidate the possible ameliorating effect of D3 receptor activation on parkinsonian tremor.
  
  
  RESULTS
  In experiment 1, pilocarpine (4.0mg/kg) was injected into rats intraperitoneally, and the number of rapid vertical deflections of the lower jaw was counted for 20min immediately after the injection, to evaluate TJMs. TJMs were reduced by intraperitoneal administration of pramipexole (1.0mg/kg). In experiment 2, the number of TJMs was counted after the rats received intraperitoneal administration of either apomorphine (0.25, 1.0, 4.0mg/kg) or vehicle, followed by the micro-infusion of pilocarpine (50μg/1μL/side) or vehicle into the ventrolateral striatum (VLS) via implanted guide cannulae. In experiment 3, either pramipexole (0.25, 1.0, 4.0mg/kg) or vehicle was intraperitoneally administered, followed by the micro-infusion of pilocarpine or vehicle into the VLS 30min later. Pramipexole (1.0 and 4.0mg/kg) and apomorphine (1.0 and 4.0mg/kg) significantly reduced the number of TJMs induced by micro-infusion of pilocarpine into the VLS.
  
  
  CONCLUSIONS
  These findings suggest that activation of D3, as well as D2 receptors could play important roles in the suppression of parkinsonian tremor.
authors.affiliation: Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki 889-1692, Japan; Department of Pharmacy, University of Miyazaki Hospital, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki 889-1692, Japan. Electronic address: kazuya_yasuda@med.miyazaki-u.ac.jp.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Yasuda
authors.affiliation: Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki 889-1692, Japan. Electronic address: abehiro@med.miyazaki-u.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Abe
authors.affiliation: Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki 889-1692, Japan. Electronic address: go_koganemaru@med.miyazaki-u.ac.jp.
authors.forename: Go
authors.initials: G
authors.lastname: Koganemaru
authors.affiliation: Division of Neurobiology, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki 889-1692, Japan. Electronic address: ikedat@med.miyazaki-u.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Department of Pharmacy, University of Miyazaki Hospital, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki 889-1692, Japan. Electronic address: arimori@med.miyazaki-u.ac.jp.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Arimori
authors.affiliation: Department of Psychiatry, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki 889-1692, Japan. Electronic address: ishiday@med.miyazaki-u.ac.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ishida
mesh_terms: D000818:Animals; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D001058:Apomorphine / Q000627:therapeutic use; D052160:Benzothiazoles / Q000627:therapeutic use*; D004195:Disease Models, Animal; D057967:Infusions, Intraventricular; D007274:Injections, Intraperitoneal; D008297:Male; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000188:drug therapy*; D010862:Pilocarpine / Q000008:administration & dosage / Q000494:pharmacology*; D000077487:Pramipexole; D051381:Rats; D017207:Rats, Sprague-Dawley; D066328:Ventral Striatum / Q000187:drug effects*
chemical_list: D000978:Antiparkinson Agents; D052160:Benzothiazoles; D010862:Pilocarpine; D000077487:Pramipexole; D001058:Apomorphine
keywords: Apomorphine; Parkinsonism; Pramipexole; Tremulous jaw movement; Ventrolateral striatum