Analysis of benzodiazepine binding sites in rat pituitary gland

Benzodiazepine binding sites in rat pituitary gland were investigated by equilibrium binding assays in vitro. Using [3H]flunitrazepam [( 3H]FNM), specific binding was demonstrated in both anterior and neurointermediate lobes. Clonazepam and Ro 5-4864 were used to discriminate the binding to central and peripheral-type sites. Both types of binding site were found to be relatively concentrated in the neurointermediate lobe. Scatchard analysis demonstrated that Kd values for [3H]FNM for the two types of sites were similar to those reported in other areas.