Proconvulsant effect of papaverine on penicillin-induced epileptiform activity in rats.

AIM Papaverine is a vasodilator agent that is an opium alkaloid. It exhibits its effects by inhibiting phosphodiesterase enzyme. Papaverine administration is widely used to avoid symptomatic vasospasm after subarachnoid hemorrhage. We aim in this research to study the effects of papaverine on the epileptic discharges stimulated by penicillin. MATERIAL AND METHODS Adult female Wistar rats (220±30 g) were included in this research (n=30). Rats were anesthetized with urethane (1.25 g/kg) and then the left cerebral cortex was reached by opening a burr hole with a drill. Penicillin G sodium salt (500 IU) (200 IU/1 µl) was injected into the left lateral ventricle to produce epileptiform activity. Thirty minutes before penicillin G sodium injection, papaverine was administered at doses of 5, 10, 20 or 40 mg/kg intraperitoneally. RESULTS There was no significant difference in spike frequency between the control group and the groups given 5 mg/kg, 10 mg/kg or 40 mg/kg papaverine, while 20 mg/kg papaverine significantly increased the spike frequency (p<0.05). CONCLUSION This study demonstrates that papaverine augments the epileptiform activity produced by penicillin injection. It is important to remember that papaverine might induce convulsions in patients who have epilepsy. More research is required to understand the mechanisms of the proconvulsant influence of papaverine in epilepsy.