Benzodiazepine inverse agonist, DMCM- and peripheral agonist, Ro 5-4864-induced convulsions in mice: effect of adenosinergic agents.

Adenosinergic agents such as adenosine, 2-chloro-adenosine, N6-cyclohexyladenosine produced dose-dependent protective effect against DMCM- and Ro 5-4864-induced convulsions and mortality. N6-cyclohexyladenosine produced most significant protective e ect against Ro 5-4864-induced convulsions whereas 2-chloroadenosine was more effective than N6-cyclohexyladenosine in antagonising DMCM-induced convulsions. Pretreatment of animals with subprotective doses of adenosine and dipyridamole significantly prolonged the latencies for the onset of myoclonic jerks and convulsions due to both DMCM and Ro 5-4864. DMCM and Ro 5-4864-induced mortality rate was also significantly reduced by pretreatment with subprotective doses of adenosine and dipyridamole. Similarly, subprotective doses of adenosine and diazepam further delayed the latencies for myoclonic jerks and convulsions due to DMCM and Ro 5-4864 treatment. The results suggest that adenosine and adenosine receptor agonists, 2-chloroadenosine and N6-cyclohexyladenosine are protective against both DMCM- and Ro 5-4864-induced convulsions. It is suggested that adenosinergic agents via activation of central A1 adenosine receptors may modulate the convulsant effects mediated by DMCM and Ro 5-4864. This study further supports the notion that adenosinergic mechanisms mediate neuroprotective e ects in the central nervous system.