Binding of beta-carboline-3-carboxylic acid ethyl ester to mouse brain benzodiazepine receptors in vivo

Abstract

beta-Carboline-3-carboxylic acid ethyl ester (beta-CEE) displaced [3H] flunitrazepam from the mouse brain benzodiazepine receptor in vivo with an i.v. ED50 of 2.1 mg/kg, an i.p. ED50 and 53.4 mg/kg, and an i.g. ED50 of 450 mg/kg. At 2.1 mg/kg i.v. beta-CEE displaced 37 +/- 9% of the label from hippocampal membranes and 76 +/- 7% from cerebellar membranes. The results suggest that the in vitro binding specificity of beta-CEE is also expressed in vivo and that the drug may act in vivo by binding to the benzodiazepine receptor.