title: 7-Nitroindazole, a nitric oxide synthase inhibitor, has anxiolytic-like properties in exploratory models of anxiety.
abstract: The action of the novel nitric oxide synthase (NOS) inhibitor 7-nitroindazole (7-NI) was studied in different exploratory models of anxiety. In the rat plus-maze test, 7-NI potently increased time spent on open arms and percentage of open arm visits in a dose dependent manner with the minimal effective dose of 40 mg/kg. 7-NI caused an anxiolytic-like effect in the rat social interaction test. The minimal dose increasing social interaction time was 20 mg/kg. However, the drug also produced a clear sedative effect occurring even at smaller doses (10 mg/kg) in the open field test. 7-NI also showed an anxiolytic-like profile in the mouse light-dark compartment test and in the elevated plus-maze test, but the doses required were higher (80-120 mg/kg) than in rat models. Also, the sedative effect occurred at these doses in open field. We failed to demonstrate any effect of L-arginine either in the rat elevated plus-maze test or in the open field test at doses up to 600 mg/kg IP. These results indicate that there are no major interspecies differences between rats and mice in respect of action of 7-NI. The clear anxiolytic-like action of the nitric oxide synthase inhibitor in four different models shows that nitric oxide is involved in the process of anxiety and that NOS could be a new target in developing anxiolytic drugs.
authors.affiliation: Department of Physiology, University of Tartu, Estonia.
authors.forename: V
authors.initials: V
authors.lastname: Volke
authors.forename: A
authors.initials: A
authors.lastname: Soosaar
authors.forename: S
authors.initials: S
authors.lastname: Kõks
authors.forename: M
authors.initials: M
authors.lastname: Bourin
authors.forename: P T
authors.initials: PT
authors.lastname: Männistö
authors.forename: E
authors.initials: E
authors.lastname: Vasar
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000523:psychology*; D001522:Behavior, Animal / Q000187:drug effects; D007191:Indazoles / Q000494:pharmacology*; D007398:Interpersonal Relations; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D007191:Indazoles; D018696:Neuroprotective Agents; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; C080122:7-nitroindazole