The effects of intraperitoneal injection of N6-cyclohexyladenosine (CHA, a selective adenosine A1 receptor agonist) and 8-cyclopenthyle-I-3-dimethylexanthine (CPT, a selective adenosine A1 receptor antagonist) on entorhinal cortex-kindled seizures were investigated. Fully entorhinal cortex-kindled rats received normal saline (control), CHA (0.06, 0.12 and 0.25 mg/kg) or CPT (0.06 and 0.12 mg/kg) and 15 min later were stimulated at AD threshold. Obtained data showed that intraperitoneal administration of CHA (0.12 and 0.25 mg/kg) reduced entorhinal cortex afterdischarge duration (ADD), duration of stage 5 of the seizure (S5D) and seizure duration (SD) at 15 min post-drug injection. The latency for stage 4 of the seizure (S4L) also increased at these doses. At the dose of 0.06 mg/kg, CHA only reduced S5D. Intraperitoneal injection of CPT increased ADD only at 0.12 mg/kg, but not at 0.06 mg/kg. Pretreatment of animals with CPT (0.06 mg/kg), 5 min before CHA (0.12 mg/kg) blocked the anticonvulsant effects of CHA. Obtained results may indicate that activity of adenosine A1 receptors reduces the severity of entorhinal cortex-kindled seizures.

Keywords: Seizure; Kindling; Entorhinal cortex; Adenosine