Effect of alprazolam on the benzodiazepine receptors in brain of experimental animals.

We studied the effect of the benzodiazepine derivative alprazolam on [3H]-flunitrazepam binding with a brain synaptosomal fraction of experimental animals in vitro and in vivo. The in vivo experiments were carried out in intact cats and mice with social isolation. Alprazolam did not change the density of benzodiazepine receptors in intact animals, but restored their number, strongly reduced in a model of social aggression.