Objective: In the present study we evaluated the involvement of L-arginine/nitric oxide (NO) pathway in the antidepressant-like effects of acute lithium administration in the mouse forced swimming test (FST).
Methods: It was an experimental study. Forced swimming test was applied as a model for depression; the immobility time was considered as an indicator of depression. In the present study, the effects of lithium (0.5-100 mg/kg), the nonselective NO synthase (NOS) inhibitor, NpGP -nitro-L-arginine methyl ester (L-NAME, 10-100 mg/kg), the specific neuronal NOS inhibitor, NpwP-propyl-L-arginine (L-NPA, 5-15 mg/kg), and the NO precursor L-arginine (750 mg/kg) were evaluated.
Results: Lithium, at 30 and 100 mg/kg, significantly reduced the immobility times of mice in the FST, whereas at lower doses (0.5, 5 and 10 mg/kg) had no effect on the immobility time. L-NAME, at 10 and 30 mg/kg, and LNPA, at 5 and 15 mg/kg, had no significant effects on the FST, whereas they significantly decreased the immobility time at 100 and 30 mg/kg, respectively. Combination of non effective dose of lithium (10 mg/kg) with low doses of L-NAME (30 mg/kg) or L-NPA (15 mg/kg) significantly reduced the immobility time in the FST. Non-effective dose of L-arginine (750 mg/kg) significantly reversed the antidepressant-like effect of 30 mg/kg lithium in the FST.
Conclusion: These data indicate the involvement of L-arginine/NO pathway in the antidepressant-like effect of lithium in the mouse FST and also might suggest the concurrent administration of NOS inhibitors and lithium as an appropriate strategy for treatment of depression.
Type of Study:
Research |
Subject:
Special Received: 2007/08/8 | Accepted: 2007/10/24 | Published: 2007/12/22