Influence of antidepressant drugs on macrophage cytotoxic activity in rats.

The aim of the study was to evaluate the in vivo and in vitro effects of antidepressant drugs on cytotoxic activity of rat spleen macrophages. In the in vivo experiment, rats were injected subcutaneously with two different doses (2 or 10 mg/kg) of desipramine, fluvoxamine and fluoxetine. The drugs were given once, for 2, 4 or 8 weeks. In the in vitro experiment, spleen macrophages were cultured with three different concentrations of desipramine (3.75, 0.75, or 0.075 mM), fluvoxamine (3.14, 0.62, or 0.062 mM), and fluoxetine (3.23, 0.64, or 0.064 mM) for 72 h. The cytotoxic activity of macrophages was evaluated by measuring the lysis of ((51)Cr) chromate-labelled P-815 target cells. In the in vivo experiment, a single dose of fluvoxamine (2 and 10 mg/kg) and fluoxetine (10 mg/kg) significantly decreased macrophage cytotoxic activity. Fluvoxamine (2 and 10 mg/kg), fluoxetine (10 mg/kg) and desipramine (10 mg/kg) administrated for 14 days also decreased macrophage cytotoxic activity. Twenty-eight day treatment with desipramine (2 and 10 mg/kg) decreased macrophage cytotoxic activity. Desipramine, fluvoxamine and fluoxetine given for 56 days did not affect macrophage cytotoxic activity. In the in vitro experiment, antidepressant drugs did not affect the cytotoxic activity of macrophages. The results of the study indicate that the effects of antidepressant drugs on macrophage cytotoxic activity depend on the drug type, dose and duration of the treatment.