title: Determination of acute toxic effects in mice following exposure to methyl bromide.
abstract: An inhalation system was designed and constructed for acute nose exposure of mice to methyl bromide. Animals were exposed for 1 h to concentrations ranging from 0.87 to 5.93 mg/l. Mice exposed to concentrations up to 1.72 mg/l did not exhibit any indication of developing a toxic response. Animals exposed to concentrations to 2.20 and 2.70 mg/l exhibited significantly decreased lung and liver weights when compared to controls. Animals exposed to concentrations above 3.50 mg/l exhibited kidney lesions. At concentrations of 3.82 mg/l and above, animals exhibited abnormal clinical signs, weight loss, and mortality. In addition, at 4.70 mg/l, a liver lesion was observed. At concentrations above 5.77 mg/l, pathological changes were observed in the color and a decreased motor coordination was evident. Methyl bromide exposures of up to 3.82 mg/l did not affect the ability of mice to recall a single-task passive-avoidance test. The 1-h LC50 of methyl bromide in mice via inhalation was determined to be 4.68 mg/l (approximately 1200 ppm). The dose-response curve was quite steep and the LC10 to LC90 range of mortality was contained within a doubling of concentration.
mesh_terms: D000818:Animals; D001273:Atmosphere Exposure Chambers; D001923:Brain Chemistry; D002855:Chromatography, Thin Layer; D005470:Fluorometry; D005684:Gait / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D006842:Hydrocarbons, Brominated / Q000633:toxicity*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D007928:Lethal Dose 50; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D014018:Tissue Distribution
chemical_list: D006842:Hydrocarbons, Brominated; C005218:methyl bromide; D005978:Glutathione