Effect of Veratrine, Tetraethylammonium and Diphenylhydantoin on Potassium Release by Rat Hippocampus

Abstract

Rat dorsal hippocampus was perfused with veratrine, diphenylhydantoin and tetraethylammonium solutions. The effect of these agents on K⁺ contents was determined in unstimulated animals, and in others in which 10 pulses/sec were delivered to the dorsal fornix during 25 min. This stimulation produced a K⁺ release in the hippocampus of rats perfused with a control saline solution. Veratrine increased, and tetraethylammonium and diphenylhydantoin reduced the K⁺ loss by stimulation. These observations suggest that the antiepileptic action of diphenylhydantoin may be similar to that of tetraethylammonium, namely, due to a blockade of K⁺ release by stimulated fibers or cells within the hippocampus.