Immunoenhancing effects of alprazolam, a benzodiazepine receptor agonist

The effects of alprazolam (ALP), a triazolobenzodiazepine with high affinity for "central" benzodiazepine receptors, were examined on several parameters of immune function in mice. NK, MLR, and mitogen-induced lymphocyte proliferation were all significantly increased 2 hr after administration of low doses (0.02-1.0 mg/kg) of ALP. Twenty four hr later, similar but less robust immunoenhancing effects were observed. These measures of immune functions were not affected by higher doses of ALP (5-10 mg/kg). The immunoenhancing effects of ALP did not appear related to serum corticosterone levels. These and other findings demonstrate that the GABA/benzodiazepine receptor chloride channel complex can bidirectionally modulate immune function.