The aim of the present study was to obtain information about the effects of pentylenetetrazol-induced status epileptious (SE) and streptozotocin-induced diabetes on brain cortex Ca2+ ATPase activity. Treatment with pentylenetetrazol (PTZ) and streptozotocin (STZ) to rats resulted in significant decrease in brain cortex Ca2+ ATPase activity as compared with controls. However, PTZ-treated diabetic rats had a slight but non-significant decrease in enzyme activity. Treatment with PTZ caused a more pronounced effect in inhibiting enzyme activity than that of treatment with STZ. Our results concluded that reduced brain cortex Ca2+ ATPase activity following PTZ and STZ treatments to rats, may be an initial biochemical lesion which triggers a sequence of events which may culminate in cell death.