Changes in purine levels and adenosine receptors in kindled seizures in the rat

Abstract

Adenosine is an inhibitory modulator of neuronal activity and its possible involvement in seizures is of interest. We have examined changes in adenosine, its metabolites and receptors in brains of hippocampus-kindled rats, a model of partial epilepsy. Purine levels were measured by in vivo microdialysis and showed a small increase in adenosine and a dramatic increase in its metabolites after kindled seizures. Adenosine A1 receptor binding using [H]DPCPX was unaltered after seizures, whereas A1 agonist stimulated binding of GTP[gamma-S] and A1 mRNA expression increased in the CA3 and other regions. Striatal adenosine A2A mRNA and receptor binding with [H]SCH-58261 decreased. These findings indicate that kindled seizures increase adenosine release and metabolism and induces adaptive changes in adenosine receptors.