Low magnesium induced epileptiform discharges in neocortical slices (guinea pig): increased antiepileptic efficacy of organic calcium antagonist verapamil with elevation of extracellular K+ concentration.
1. The antiepileptic effect of the organic calcium antagonist verapamil on low Mg2+ induced epileptiform discharges in the neocortex was tested. 2. The experiments were carried out on slices of the frontal neocortex (guinea pigs). Verapamil was tested at normal (4 mmol/l) and elevated (8 mmol/l) KCl levels. 3. Verapamil (40, 60 mumol/l) suppressed epileptiform activity in any case. 4. With elevated K+ concentration the suppressive effect of verapamil was significantly accelerated. 5. Epileptic activity reappeared when verapamil was omitted from the Mg(2+)-free superfusate.
Institut für Physiologie, Universität, Münster, F.R.G.
H
H
Straub
R
R
Köhling
E J
EJ
Speckmann
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000503:physiopathology; D017034:Epilepsy, Frontal Lobe / Q000188:drug therapy* / Q000503:physiopathology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D011188:Potassium / Q000378:metabolism*; D014700:Verapamil / Q000494:pharmacology*
D000927:Anticonvulsants; D014700:Verapamil; D008274:Magnesium; D011188:Potassium