The role of magnesium sulfate in prevention of seizures induced by pentylenetetrazole in rats.

Magnesium sulfate (MgSO₄) has been used to prevent seizures in eclampsia. This study examined the central effects of MgSO₄ on different types of pentylenetetrazole (PTZ)-induced seizures. Male Wistar rats were submitted to intracerebroventricular (ICV) administration of MgSO₄ at different doses followed by intraperitoneal administration of PTZ. The latency to the onset of the first seizure induced by PTZ was significantly increased by ICV administration of MgSO₄ at a dose of 100 µg compared to the control treatment. In addition, the total period during which animals presented with seizures was significantly reduced at this dose of MgSO₄. Furthermore, the latency to the onset of the first partial complex seizure was significantly increased by the lowest dose of MgSO₄. However, a high dose of MgSO₄ had no effect or even potentiated the effect of PTZ. These results suggest that, depending on the dose, MgSO₄ may be important in prevention of epileptic seizures.