Dopaminergic mediation of a behavioral effect of l-cathinone.
Ten male rats were trained to discriminate between the stimulus properties of 0.6 mg/kg l-cathinone and saline in a two-lever food-motivated operant task. Once trained, rats showed a dose-dependent increase in discrimination over a dosage range of 0.15-1.2 mg/kg l-cathinone. Analysis of this dose-response relationship indicated an ED50 of 0.27 mg/kg. Pretreatment with 0.2 mg/kg of the specific dopamine blocking drug haloperidol increased this ED50 to 0.47 mg/kg and significantly decreased discriminative performance when co-administered with either 0.15, 0.3, or 0.6 mg/kg l-cathinone. Since the dose-effect curves for cathinone with and without haloperidol pre-treatment were parallel, it is suggested that l-cathinone, the active constituent in khat, produces its discriminative properties, in part, by mediation of dopaminergic neuronal systems.
D000470:Alkaloids / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000187:drug effects*; D003216:Conditioning, Operant; D003463:Cues; D004193:Discrimination Learning; D004298:Dopamine / Q000502:physiology*; D004347:Drug Interactions; D005502:Food; D006220:Haloperidol / Q000008:administration & dosage; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D009435:Synaptic Transmission / Q000187:drug effects
D000470:Alkaloids; C023665:cathinone; D006220:Haloperidol; D004298:Dopamine