The effect of chronic (10 days) administration of methylxanthines,
caffeine,
IBMX and
theophylline on acute
ethanol-induced motor
incoordination has been investigated in the mice. In animals that received
caffeine, 45 and 90 mg/kg/24 h,
ethanol, 1.5 g/kg, produced motor
incoordination significantly greater compared to that in the control groups. Significantly greater
ethanol-induced motor
incoordination was seen in animals fed
IBMX, 30 and 60 mg/kg/24 h, compared to controls.
Ethanol-induced increased motor
incoordination in
caffeine and
IBMX-fed animals was also associated with significantly greater 3H-R-PIA binding in whole brains compared to tap water controls indicating an increase in brain
adenosine binding sites. However neither motor
incoordination nor 3H-R-PIA binding was altered in
theophylline 75 and 150 mg/kg/24 h, fed animals. The increased motor
incoordination associated with increased
adenosine binding sites in the brains of
caffeine and
IBMX-fed animals suggests an involvement of central
adenosine mechanisms in the motor incoordinating effect of
ethanol and further supports our earlier suggestion for the role of
adenosine in some of the central effects of
ethanol.