title: Pramipexole at a Low Dose Induces Beneficial Effect in the Harmaline-induced Model of Essential Tremor in Rats.
abstract: OBJECTIVE
  The aim of the study was to examine the effects of preferential agonists of dopamine D3 receptors: pramipexole and 7-OH-DPAT on the harmaline-induced tremor in rats (a model of essential tremor, ET). To study receptor mechanisms of these drugs, rats were pretreated with dopamine D3 receptor antagonists--SB-277011-A and SR-21502, an antagonist of presynaptic D2/D3 receptors--amisulpride, or a nonselective antagonist of D2-like receptors, haloperidol, at a postsynaptic dose.
  
  
  METHODS
  For tremor measurement, fully automated force plate actimeters were used and data were analyzed using fast Fourier transform.
  
  
  RESULTS
  Harmaline (15 mg/kg ip)-triggered tremor was manifested by an increase in the power within 9-15 Hz band (AP2). Pramipexole administered at a low (0.1 mg/kg sc), but not higher doses (0.3 and 1 mg/kg sc), and 7-OH-DPAT (0.1, 0.3, and 1 mg/kg sc) reversed the harmaline-increased AP2. None of the examined dopamine antagonists: SB-277011-A (10 mg/kg ip), SR-21502 (15 mg/kg ip), haloperidol (0.5 mg/kg ip), or amisulpride (1 mg/kg ip) influenced the above effect of dopamine agonists.
  
  
  CONCLUSIONS
  The present study indicates that pramipexole reduces the harmaline-induced tremor, which may suggest its beneficial effects in ET patients. However, mechanisms underlying its action are still unclear and need further examination.
authors.affiliation: Department of Neuro-Psychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Kosmowska
authors.affiliation: Department of Neuro-Psychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Wardas
authors.affiliation: Department of Neuro-Psychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
authors.forename: Urszula
authors.initials: U
authors.lastname: Głowacka
authors.affiliation: Department of Chemistry, Southern Research Institute, Birmingham, AL, USA.
authors.forename: Subramaniam
authors.initials: S
authors.lastname: Ananthan
authors.affiliation: Department of Neuro-Psychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
authors.forename: Krystyna
authors.identifier: http://orcid.org/0000-0002-8381-6632
authors.initials: K
authors.lastname: Ossowska
mesh_terms: D000077582:Amisulpride; D000818:Animals; D018726:Anti-Dyskinesia Agents / Q000008:administration & dosage*; D052160:Benzothiazoles / Q000008:administration & dosage*; D004195:Disease Models, Animal; D018491:Dopamine Agonists / Q000008:administration & dosage; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D020329:Essential Tremor / Q000188:drug therapy* / Q000503:physiopathology; D006220:Haloperidol / Q000494:pharmacology; D006246:Harmaline; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D009068:Movement / Q000187:drug effects; D009570:Nitriles / Q000494:pharmacology; D000077487:Pramipexole; D011725:Pyridines / Q000494:pharmacology; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D050637:Receptors, Dopamine D3 / Q000378:metabolism; D013469:Sulpiride / Q000031:analogs & derivatives / Q000494:pharmacology; D044005:Tetrahydroisoquinolines / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D018726:Anti-Dyskinesia Agents; D052160:Benzothiazoles; C000607792:DRD2 protein, rat; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; C493595:Drd3 protein, rat; D007093:Imidazoles; D009570:Nitriles; D011725:Pyridines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C409982:SB 277011; C000593313:SR 21502; D044005:Tetrahydroisoquinolines; D013764:Tetrahydronaphthalenes; D013469:Sulpiride; D000077582:Amisulpride; D000077487:Pramipexole; D006246:Harmaline; D006220:Haloperidol; C031349:7-hydroxy-2-N,N-dipropylaminotetralin
keywords: Cerebellum; Dopamine receptors; Essential tremor; Harmaline-induced tremor; Pramipexole