Effects of adrenalectomy and repeated convulsions on responses of rats to flurothyl

In studies to determine the influence of adrenocortical deficiency on sensitivity to the volatile convulsant flurothyl, administered by inhalation, adult male rats were convulsed at 3-day intervals. Repetitive testing alone was found to decrease the latency to maximal convulsion in controls. However, adrenalectomy not only counteracted this effect, but also increased maximal seizure latency above pre-operative levels if the rats were maintained on tap water. In addition, adrenalectomy decreased the intensity of the maximal convulsion, but increased susceptibility to the minimal convulsive response (myoclonic jerk). This last effect is in accord with other reports of increased susceptibility to various experimentally-induced seizures after adrenalectomy, but in contrast to results with pentylenetetrazol seizures. Drinking 0.9 % NaCl reduced all effects of adrenalectomy on flurothyl convulsions.