title: Antidepressant-like effect of 7-nitroindazole in the forced swimming test in rats.
abstract: BACKGROUND
  There is some strong evidence about the role of nitric oxide (NO) as an intercellular messenger in central physiological mechanisms. NO is synthesized from L-arginine by nitric oxide synthase (NOS), as a response to activation of N-methyl-D-aspartate (NMDA) receptors by excitatory amino acids. NMDA receptor antagonists also produce antidepressant-like actions in preclinical models.
  
  
  OBJECTIVE
  In the present study, the involvement of NO in the mechanism of depression was investigated. 7-Nitroindazole (7-NI) (15, 30, 60, 90 mg/kg IP), a selective inhibitor of neuronal NOS was examined.
  
  
  METHODS
  The Porsolt forced swimming test (FST) has been used as a test for screening new antidepressant agents.
  
  
  RESULTS
  7-NI dose-dependently decreased the immobility time in FST, but produced no significant change in locomotor activity in naive rats. Neither L-arginine, nor D-arginine (100 mg/kg) affected the immobility time in the FST or revealed any effect on locomotion. L-Arginine but not D-arginine, given 10 min before 7-NI, reversed the 7-NI-induced effect on immobility time.
  
  
  CONCLUSIONS
  Our findings suggest that NO might be an important modulator of depression in rats.
authors.affiliation: Kocaeli University, Faculty of Medicine, Department of Pharmacology, Turkey. ferden@ato.org.tr
authors.forename: F
authors.initials: F
authors.lastname: Yildiz
authors.forename: B F
authors.initials: BF
authors.lastname: Erden
authors.forename: G
authors.initials: G
authors.lastname: Ulak
authors.forename: T
authors.initials: T
authors.lastname: Utkan
authors.forename: N
authors.initials: N
authors.lastname: Gacar
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001120:Arginine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007103:Immobilization; D007191:Indazoles / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming; D013997:Time Factors
chemical_list: D000928:Antidepressive Agents; D007191:Indazoles; D001120:Arginine; C080122:7-nitroindazole