Protective effect of melatonin on methylmercury-Induced mortality in mice.
Effect of melatonin on the mortality in methylmercury chloride (MMC)-intoxicated mice was evaluated. Mice were given MMC in the diet (40 mg Hg/g) with or without melatonin in drinking water (20 mg/ml) for 5 weeks. In the control group, given MMC alone, 4 of 10 mice began to show neurological signs (e.g., abnormal righting reflex, staggering gaitfallen and posture on its side) concomitant with loss of body weight 4-7 days before death. This group also showed 60% of survival rate on the 35th day. However, the treated group, concomitantly given melatonin, showed a 100% of survival rate on the 35th day, although 1 of 10 mice began to show the neurological signs on the 33rd day. The level of thiobarbituric acid reactive substance in the brain, as an indication of oxidative damage, showed a significant decrease in the treated group compared with the control group. Thus, the 100% survival rate in the treated group may be partly due to antioxidative effect of melatonin on the MMC induced neurotoxicity.
Kim
C Y
CY
Department of Environmental Health Sciences, Tohoku University School of Medicine, Sendai, Japan.
Nakai
K
K
Kameo
S
S
Kurokawa
N
N
Liu
Z M
ZM
Satoh
H
H
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D008628:Mercury / Q000378:metabolism; D008767:Methylmercury Compounds / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D051379:Mice; D008813:Mice, Inbred ICR; D009420:Nervous System / Q000187:drug effects / Q000503:physiopathology; D009498:Neurotoxins / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D008767:Methylmercury Compounds; D009498:Neurotoxins; D017392:Thiobarbituric Acid Reactive Substances; D008628:Mercury; D008550:Melatonin; C004925:methylmercuric chloride