Antidepressant-like properties of zinc in rodent forced swim test

The effects of zinc, the N-methyl-D-aspartate glutamate receptor inhibitor, were studied in mice and rats using the forced swim test. Zinc (ZnSO4) in a dose of 30 mg/kg and imipramine (30 mg/kg), reduced the immobility time i n the forced swim test in both species. Moreover, combined treatment in thi s test with zinc and imipramine at their ineffective doses (1 and 5 mg/kg, respectively) induced a statistically significant effect in rats. The doses active in the forced swim test reduced (in mice) or did not affect (in rat s) locomotor activity. The results obtained indicate that zinc induces an a ntidepressant-like effect and enhances the effect of imipramine in the forc ed swim test, suggesting a potential antidepressant activity of zinc in hum ans. (C) 2001 Elsevier Science Inc.