Effects of phenytoin and flunarizine on the rise in extracellular potassium induced by repetitive stimulation of rat cerebral cortex.
At a critical intensity of repetitive stimulation, [K+]0 in cerebral cortex increases rapidly to a "ceiling" value of 10-12 mM. Phenomena related to this rapid regenerative increase in [K+]0 were investigated using K+-sensitive microelectrodes. The critical intensity required to induce this rise was found to be increased by phenytoin (90 mg/kg preload + 30 mg/kg presurgery) but not by flunarizine (30 mg/kg preload + 10 mg/kg presurgery), when the stimulus (20 Hz, 0.4 ms pulse duration, 5 or 40 s train duration) was applied to a 1 mm2 area of parietal neocortex in alfentanil-anesthesized rats. Flunarizine and phenytoin appear to differ in their mechanisms of anti-epileptic action.
Reid
K H
KH
Department of Physiology, University of Louisville.
Marrannes
R
R
Wauquier
A
A
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D013181:Cortical Spreading Depression / Q000187:drug effects; D004558:Electric Stimulation; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism*; D005444:Flunarizine / Q000494:pharmacology*; D008297:Male; D010672:Phenytoin / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D010672:Phenytoin; D005444:Flunarizine; D011188:Potassium