Effects of diltiazem on hyperthermia induced seizures in the rat pup.

1. We studied the effects of a calcium antagonist diltiazem, as well as diazepam and phenytoin on hyperthermia induced seizures in unrestrained 15 day-old rats. 2. Saline injected animals exposed to an ambient temperature of 40 degrees C showed a gradual increase in body temperature reaching a maximum of 42 +/- 0.1 degree C at 50 min. 3. At this time all rats pups had generalized seizures. 4. Similar results were obtained when the animals were pretreated with phenytoin (100% showed seizures). 5. Animals receiving diltiazem had a temperature of 41.5 +/- 0.1 degree C at 90 min of exposure to 40 degrees C environment. 6. However, diltiazem completely prevented seizures. 7. The rats treated with diazepam showed lower temperature than in saline, diltiazem and phenytoin groups and no seizures were observed in this experimental group.