The role of opioid receptor sub-types in tifluadom-induced feeding

Abstract

Abstract There is now considerable evidence that opioid agonists and benzodiazepines increase food and water intake in a variety of animal species. The appetitive effects of the novel opioid-benzodiazepine tifluadom have been investigated. (±)-Tifluadom significantly increased food intake in freely-feeding rats. This stimulation of appetite was attributable principally to the activity of the (+)-isomer. Furthermore tifluadom-induced feeding was blocked by the opioid antagonists naloxone, naltrexone, Mr 1452 and Mr 2266 but not by the δ-opioid receptor antagonist ICI 154, 129, or by the benzodiazepine antagonist Ro 15–1788. These results suggest that tifluadom exerts its effect on food intake by interaction with opioid as opposed to benzodiazepine receptors and that this activity is mediated by κ and/or μ- rather than δ-opioid receptor sub-types.