Role of Melatonin Receptors in Hyperthermia-Induced Acute Seizure Model of Rats.

Melatonin is a neurohormone that has anticonvulsant activity in different experimental seizure models including hyperthermic febrile seizure. However, the mechanisms of this effect are not clear at the receptor level. The aim of the study was to determine which melatonin receptors involve in the hyperthermic febrile seizure model. 22-30 days Wistar male rats were used, and in children, it corresponds to 1.5-2 years. Groups were performed as (1) control, (2) ethanol/saline, (3) DMSO, (4) melatonin (MT), (5) MT + luzindole (LUZ), (6) MT + K-185, (7) MT + prazosin (PRZ), (8) MT + LUZ + K-185, (9) MT + LUZ + PRZ, (10) MT + K-185 + PRZ, and (11) MT + LUZ + PRZ + K-185. The hyperthermic febrile seizure pattern was established by keeping the rats in 45 °C hot water, and the latency, duration, and severity of seizures were determined in all groups. MT, LUZ, K-185, and PRZ were given 15, 45, 15, and 30 min before the induction of seizure, respectively. It was observed that melatonin shortened the duration of seizure, reduced the severity, and did not affect latency and that these effects were not completely blocked by receptor antagonists when compared with control, ethanol/saline, and DMSO groups. In conclusion, the fact that the anticonvulsant effect of melatonin is not completely blocked by all melatonin receptor antagonists. We can conclude that a multimodal mechanism may be responsible for the effect of melatonin receptors alone on the anticonvulsant effect of melatonin. It will be useful to design new pharmacological studies to make the subject clear.