title: Lack of effect of Nomega-nitro-L-arginine methyl ester on bromocriptine-induced locomotor sensitization in mice.
abstract: The present study was designed to investigate the effects of Nomega-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitory agent, on bromocriptine-induced locomotor sensitization in mice. Adult male Swiss-Webster mice (26-32 g) were the subjects. Saline or L-NAME (15-60 mg/kg) was injected to mice intraperitoneally 30 min before bromocriptine (5 mg/kg), and locomotor activity was recorded for 240 min in an open field activity monitoring system. This procedure lasted for 2 weeks, once in 2 days from Monday to Friday, six sessions in total. After a 2-day drug-free period, a challenge injection of bromocriptine (5 mg/kg) or vehicle was administered by all groups of mice. Other groups of mice treated with bromocriptine according to the aforementioned procedure except L-NAME pretreatments were challenged with saline or L-NAME (15-60 mg/kg) plus bromocriptine (5 mg/kg) after a 2-day drug-free period. Bromocriptine produced a significant locomotor sensitization. L-NAME (15-60 mg/kg) did not have any significant effect on the development and expression of bromocriptine-induced locomotor sensitization in mice. Meanwhile, the data also imply that NO-related mechanisms may not be responsible for bromocriptine-induced locomotor sensitization in mice.
authors.affiliation: Department of Medical Pharmacology, Psychopharmacology Research Unit, Gulhane Military Medical Academy, Etlik 06018, Ankara, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Kayir
authors.forename: Mert
authors.initials: M
authors.lastname: Ceyhan
authors.forename: Oğuzhan
authors.initials: O
authors.lastname: Yavuz
authors.forename: I Tayfun
authors.initials: IT
authors.lastname: Uzbay
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001971:Bromocriptine / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*
chemical_list: D018491:Dopamine Agonists; D004791:Enzyme Inhibitors; D001971:Bromocriptine; D019331:NG-Nitroarginine Methyl Ester