Suppression of feeding by naloxone in rat: a dose-response comparison of anorexia and conditioned taste aversion suggesting a specific anorexic effect.

The dose-related suppression of feeding by naloxone (0.25-15.0 mg/kg), either by injection before feeding, or by conditioning taste aversion (CTA), was compared. The weaker suppression found for CTA at low (below 0.75 mg/kg) and high (above 5.0 mg/kg) doses suggests that the aversive sequelae of naloxone injection cannot account fully for its suppressive effects. In turn, this suggests that naloxone exerts a specific anorexic effect. Comprehensive dose-response curves for naloxone anorexia (15 doses) and CTA (nine doses) are presented.