87ANTI-CONVULSION ACTIVITY OF TRAMADOL IN MAXIMUM ELECTRIC SHOCK SEIZURE (MES) AND PENTYLENETETRAZOL INDUCED SEIZURES IN RATSTramadol is a weak opioid analgesic in addition it inhibits reuptake of noradrenaline and serotonin. Its action described at the kappa opioid receptor or to an indirect consequence of GABA receptor modulation. The present study was designed for assessment of anti-convulsion activity of tramadol against maximal electroshock seizure (MES) and pentylenetetrazole induced-seizure in animals. Tramadol was evaluated for anti-convulsion activity at two different doses (20 and 40 mg/kg, i.p). The anticonvulsant activity of test drug was assesses against maximal electroshock seizure (MES) induced grandmal epilepsy by 150 mA current for 0.2 sec delivered via ear clip electrodes to rats and duration of tonic hind limb extension (THE) was recorded. Effect of test drug against petitmal type of epilepsy was induced by pentylenetetrazole (70 mg/kg, ip) in rats and duration of clonic convulsion was recorded in rats. Phenytoin (30 mg/kg, i.p) in MES and sodium valproate (400mg/kg, i.p) in pentylenetetrazol induced seizures were kept as standard drug treated groups. Tramadol (20 mg/kg) produced non-significant decrease (13.04%) while 40 mg/kg produced significant decrease (43.48%) in THE phase in comparison to control group in MES model. Tramadol at lower dose did not produce any effect while 40 mg/kg produced significant decrease (27.61%) in clonic seizures in pentylenetetrazole induced seizures in rats. Tramadol showed significant anticonvulsant activity in maximal electric shock induced seizures in rats may be due to activation of κ opioid receptors and pentylenetetrazol induced seizures may be through nitric oxide pathway accompanied by an increase in GABAergic tone in rats.drdjayasree@gmail.comResearch512015Maximum electric shock,Pentylenetetrazole,Seizures,TramadolJayasree D,Amitabh A KumarDepartment of Pharmacology, Madha Medical College, Chennai-600122, Tamil Nadu, India.,Department of Pharmacology, Narayana Medical College, Nellore-524002, Andhra Pradesh, India.