title: Time-dependent anticonvulsant activity of melatonin in hamsters.
abstract: The objective of the present study was to assess whether the anticonvulsant activity of melatonin displays diurnal variability in hamsters. Convulsions were induced by administering 3-mercaptopropionic acid (3-MP). There was a significant diurnal variation in 3-MP-induced convulsions, hamsters being more prone to exhibit seizures during the night than during the day. Melatonin (50 mg/kg i.p.) had a maximal anticonvulsive effect in the early evening (20:00 h). The administration at 20:00 h of the central-type benzodiazepine antagonist, Ro 15-1788, although unable by itself to modify seizure threshold, blunted the anticonvulsant response to melatonin. The results indicate that the time-dependent anticonvulsant activity of melatonin is sensitive to central-type benzodiazepine antagonism.
authors.affiliation: Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
authors.forename: D A
authors.initials: DA
authors.lastname: Golombek
authors.forename: D
authors.initials: D
authors.lastname: Fernández Duque
authors.forename: M G
authors.initials: MG
authors.lastname: De Brito Sánchez
authors.forename: L
authors.initials: L
authors.lastname: Burin
authors.forename: D P
authors.initials: DP
authors.lastname: Cardinali
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000037:antagonists & inhibitors / Q000633:toxicity; D000818:Animals; D002940:Circadian Rhythm; D006224:Cricetinae; D005442:Flumazenil / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D008297:Male; D008550:Melatonin / Q000627:therapeutic use*; D008647:Mesocricetus; D012640:Seizures / Q000139:chemically induced / Q000517:prevention & control*
chemical_list: D005442:Flumazenil; D015097:3-Mercaptopropionic Acid; D008550:Melatonin