RESUMO
The effects of prostaglandin E - analogue misoprostol on the susceptibility to pentilenetetrazol (PTZ) - induced seizures were examined in mice. Misoprostol (200-800 mug/kg), given subcutaneously 45 min before the subconvulsive dose of PTZ (30 mg/kg, i.p) provoked dose-dependent clonic-tonic seizures (30 to 100 percent) and mortality in mice. At 300 g/kg, s.c., misoprostol pretreatment significantly (p<0.05) lowered the onset latency to first convulsion as well as the latency to mortality induced by a convulsive dose of PTZ (60 mg/kg, i.p.). At this dose misoprostol was found to lower the CD50 and Ld50 values for PTZ by 21 percent and 36 percent respectively. The results suggest that prostaglandins are likely to lower the threshold for convulsions.