Effect of some drugs acting at the central-type benzodiazepine receptors on blood glucose in mice.

1. The effects of some drugs acting at the central-type benzodiazepines receptors on blood glucose levels in mice were studied. 2. Clonazepam, injected intraperitoneally in doses of 0.625-5 mg, produced a dose-dependent increase in blood glucose 30 min after administration. 3. The hyperglycaemic effect of clonazepam (2.5 mg/kg, i.p.) was dose-dependently reduced by Ro 15-1788 (10-40 mg/kg, i.v.), a benzodiazepine antagonist. 4. Ro 5-3663, a GABA antagonist which may act at the picrotoxinin site, produced a significant increase in blood glucose (5 or 10 mg/kg, i.p.); however, when given together with clonazepam (2.5 mg/kg, i.p.) attenuation of the hyperglycaemic effect was observed. 5. Pk 8165, a partial agonist, lacked an effect on blood glucose over the dose range of 5-20 mg/kg, i.p. but caused a slight increase in blood glucose in a dose of 40 mg/kg, i.p.