Antidepressant-like effect of 7-nitroindazole in the forced swimming test in rats

Yildiz F. , Erden B. F. , Ulak G. , Utkan T. , Gacar N.

PSYCHOPHARMACOLOGY, vol.149, pp.41-44, 2000 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 149
  • Publication Date: 2000
  • Doi Number: 10.1007/s002139900316
  • Title of Journal : PSYCHOPHARMACOLOGY
  • Page Numbers: pp.41-44


Rationale: 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 IF), 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. Conclusion: Our findings suggest that NO might be an important modulator of depression in rats.