Influences of different adenosine receptor subtypes on catalepsy in mice

The effects of adenosine A₁ and A₂ receptors on catalepsy were studied in mice. The adenosine agonists 5-N-ethylcarboxamide-adenosine (NECA), N⁶-phenylisopropyladenosine (PIA) and N⁶-cyclohexyladenosine (CHA) induced dose dependent catalepsy. The A₁ adenosine antagonist 8-phenyltheophylline (8-PT) potentiated catalepsy induced by NECA, R-PIA and CHA. However, theophylline did not potentiate but inhibited the responses induced by NECA, R-PIA and CHA. Neither 8-PT nor theophylline alone has any effect on catalepsy in mice. It is concluded that catalepsy induced by the adenosine agonists may be due to A₂ receptor stimulation and that the A₁ antagonism may potentiate the response.