The effects of chronic treatment with a calcium channel antagonist on two types of generalized epilepsies in rats

Pharmacol Biochem Behav. 1994 Jul;48(3):575-9. doi: 10.1016/0091-3057(94)90316-6.


Although calcium antagonists possess antiepileptic properties in various models of epilepsy, their role after chronic administration and in models for generalized absence epilepsy has not been studied. Twenty-four male Wistar rats, aged 84-94 weeks, were chronically provided with EEG electrodes. Two groups received dietary nimodipine (860 ppm) for 14 and 21 weeks, respectively, while a control group received the same rat chow without nimodipine. The EEG was recorded for 3 h to establish the effects of nimodipine on spike-wave discharges. Next, 50 mg/kg pentylenetetrazol (PTZ) was injected to establish the effects on convulsive epilepsy, and the EEG was recorded for 30 min. All animals had spontaneous spike-wave discharges (SWD), but there were no differences between the three groups. However, chronic nimodipine treatment had a significant effect on PTZ-induced seizures: the group that had been treated with nimodipine for 21 weeks showed significantly more and longer-lasting seizures than the control group. The facilitating effects of chronically administered of nimodipine on PTZ-induced seizures are striking and opposite to those reported in the literature. In a second study, nimodipine was administered acutely, but no effects of nimodipine on PTZ-induced epilepsy could be detected. It can be concluded that chronic dietary administration of a calcium antagonist induces different effects on PTZ-induced seizures than acute administration in aged Wistar rats with spontaneous occurring SWD.

MeSH terms

  • Animals
  • Calcium Channel Blockers / pharmacology*
  • Diet
  • Electroencephalography / drug effects
  • Epilepsy, Absence / physiopathology
  • Epilepsy, Generalized / chemically induced
  • Epilepsy, Generalized / genetics
  • Epilepsy, Generalized / physiopathology*
  • Epilepsy, Tonic-Clonic / physiopathology
  • Male
  • Nimodipine / pharmacology*
  • Pentylenetetrazole
  • Rats
  • Rats, Wistar


  • Calcium Channel Blockers
  • Nimodipine
  • Pentylenetetrazole