title: Antagonistic effect of melatonin against cyanide-induced seizures and acute lethality in mice.
abstract: The effect of melatonin on potassium cyanide-induced neurotoxicity was investigated in vivo. The ED50 value of potassium cyanide, as measured by induction of tonic and clonic seizures, was significantly increased by 1.5- or 1.8-fold by s.c. preinjection of melatonin (20, 100 or 345 mg/kg) in mice. The preventive effect of melatonin against potassium cyanide-induced seizures was dose dependent. The LD50 value of potassium cyanide, based on 24-h mortality, was also significantly increased by 1.3-fold by preinjection of melatonin. Potassium cyanide (8 mg/kg, s.c.) increased lipid peroxidation in whole brain of mice, and the increased lipid peroxidation was completely abolished when cyanide-induced seizures were stopped by preadministration of melatonin. These results suggest that melatonin, a pineal hormone, may protect against cyanide-induced neurotoxicity with its free radical scavenging effects in mice.
authors.affiliation: Institute of Community Medicine, University of Tsukuba, Ibaraki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yamamoto
authors.forename: H W
authors.initials: HW
authors.lastname: Tang
mesh_terms: D000818:Animals; D000931:Antidotes / Q000627:therapeutic use*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007279:Injections, Subcutaneous; D007928:Lethal Dose 50; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008550:Melatonin / Q000627:therapeutic use*; D051379:Mice; D011190:Potassium Cyanide / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000633:toxicity; D012640:Seizures / Q000139:chemically induced / Q000188:drug therapy*; D015996:Survival Rate
chemical_list: D000931:Antidotes; D008550:Melatonin; D011190:Potassium Cyanide