Electroshock raises pentylenetetrazol threshold: possible role of inosine.

A series of 15 single electroshocks administered through electrodes applied to the scalp of mice raised the threshold to pentylenetetrazol-induced seizures as determined by a tail vein infusion method. The same stimulus increased brain inosine and hypoxanthine. Phenytoin, which blocks the increase in inosine produced by this stimulus, reversed the elevation in threshold may be electroshock. The effect of electroshock on threshold may be mediated by inosine.