Zinc deficiency induces behavioral alterations in the tail suspension test in mice. Effect of antidepressants.

BACKGROUND Recently, experimental zinc deficiency has been correlated with depression-like alterations in rodents. METHODS In the first part of present study, the time course of zinc deficient diet induced alterations in the tail suspension test (TST) in mice was investigated. In the second part, the effect of imipramine and escitalopram in control and zinc-deprived for 3 weeks mice was examined in the TST. RESULTS A4- and 10-week administration of a Zn-deficient diet enhanced the immobility time in the TST (by 20% and 57%, respectively). By contrast, a 2-week period of a zinc deficient diet effected the reduction (by 24%) of the immobility time. Moreover, a 2- and 4-week (but not 10-week) of a Zn-deficient diet resulted in the reduction of the body weight (by 37% and 18%, respectively). These results indicate the developing response to zinc deficiency induced by a zinc-deficient diet. The antidepressant-like effect (reduction in the immobility time) of both drugs was significantly reduced in zinc-deprived mice, which suggests treatment-resistance induced by zinc deprivation. CONCLUSION Zinc deprivation induces "pro-depressive" behavior and alters antidepressant efficacy.