The effects of putative anxiolytic compounds (PK 8165, PK 9084 and tracazolate) on the rat corticosterone response.

The effects were investigated of three putative anxiolytics, thought to act at the GABA-benzodiazepine receptor complex, on basal corticosterone and novelty-induced rise in plasma corticosterone concentrations. The two phenylquinolines, PK 8165 and PK 9084, increased basal concentrations, but reduced the novelty-induced rise in corticosterone; these actions resemble those found with high doses of benzodiazepines. Tracazolate, a pyrazolopyridazine that enhances the binding of benzodiazepines to their receptors, was without significant effect in either situation.