ACUTE TREATMENT OF MICE WITH HIGH-DOSES OF CAFFEINE - AN ANIMAL-MODELFOR CHOREIFORM MOVEMENT

Injection of caffeine at a dose of 35 to 70 mg/kg causes choreiform (d ance-like) movements in NIH Swiss mice in a dose-dependent manner. The effect is less pronounced in mice that had chronically ingested caffe ine for 7 days. The A(2a) selective adenosine agonist ylphenylethylami no]-5'-N-ethylcarboxamidoadenosine (APEC), but not the A(1) selective agonist N-6-cyclohexyladenosine (CHA), diminished caffeine-elicited ch oreiform movement. The data suggest involvement of A(2a)-adenosine rec eptors in the appearance of choreiform movements. The dopamine antagon ist haloperidol also reduced the chorea movements elicited by caffeine , but high doses were required. The calcium-channel blocker nitrendipi ne reduced the choreiform movements. These animals could provide a mod el for further investigation of the mechanisms underlying choreiform m ovements; as well as possible therapeutic approaches to certain chorea s in humans related either to disease states (e.g., Huntington's disea se or Tourette's syndrome) or to side effects of drug treatments. (C) 1993 Wiley-Liss, Inc.