Yamano Y
Department of Hygiene and Public Health, Tokyo Women's Medical College.
Sangyo Igaku. 1991 Jan;33(1):23-30.
The objectives of this study were to determine the LC50 of methyl bromide (MeBr) and the dose-response curve and to study the detoxication effect of reduced glutathione (GSH) on MeBr poisoning in mice. 1) The LC50 of 4-h exposure to MeBr was 405 ppm in male mice with 95% confidence limits of 386-425 ppm. 2) The mortality rates of mice exposed to 500 ppm MeBr for 105, 120, 130, 140, 150 and 180 min were 0, 0, 10.7, 15.0, 85.0 and 90.0%, respectively. 3) In contrast, the mortality rate of mice pretreated with GSH (i.p 500 mg/kg; GSH-group) was only 5.3% after exposure to 500 ppm MeBr for 150 min. 4) Metabolic substances (Br-, GSH, formaldehyde, formic acid and beta-glucuronidase) were analyzed after exposure to 500 ppm MeBr and compared with the GSH-group and the distilled water treated group (DW-group). Except for GSH, concentrations of all other substances were significantly lower in the GSH-group than in the DW-group. Erythrocyte osmotic fragility test showed a significant increase in fragility in the DW-group. These results suggested that the onset of symptoms or death due to MeBr poisoning suddenly occurs at some point of concentration and time exposure. It was also shown that pretreatment with GSH effectively reduced mortality due to MeBr exposure.
本研究的目的是确定甲基溴（MeBr）的半数致死浓度（LC50）和剂量反应曲线，并研究还原型谷胱甘肽（GSH）对小鼠MeBr中毒的解毒作用。1）雄性小鼠暴露于MeBr 4小时的LC50为405 ppm，95%置信限为386 - 425 ppm。2）暴露于500 ppm MeBr 105、120、130、140、150和180分钟的小鼠死亡率分别为0、0、10.7%、15.0%、85.0%和90.0%。3）相比之下，预先经GSH处理（腹腔注射500 mg/kg；GSH组）的小鼠在暴露于500 ppm MeBr 150分钟后的死亡率仅为5.3%。4）在暴露于500 ppm MeBr后分析代谢物质（Br-、GSH、甲醛、甲酸和β-葡萄糖醛酸酶），并与GSH组和蒸馏水治疗组（DW组）进行比较。除GSH外，GSH组中所有其他物质的浓度均显著低于DW组。红细胞渗透脆性试验显示DW组的脆性显著增加。这些结果表明，MeBr中毒引起的症状或死亡在某些浓度和暴露时间点会突然发生。还表明，预先用GSH处理可有效降低因暴露于MeBr而导致的死亡率。
