Body temperature discriminates between full and partial benzodiazepine receptor agonists

The benzodiazepine full agonist loprazolam and the β-carboline ZK 93423 produced hypothermia in mice (1–30 mg/kg i.p). Maximal effects were seen at relatively low doses of these compounds. In contrast, the partial agonists Ro 17-1812 (a benzodiazepine) and ZK 91296 (a β-carboline), did not modify rectal temperature at doses up to 30 mg/kg i.p. (which would be receptor saturating). Body temperature may therefore be a useful test for discriminating between full and partial agonists at the benzodiazepine receptor.