Chronic toxicity of microencapsulated bromodichloromethane administered in the diet to Wistar rats.
A chronic feeding study was carried out in Wistar rats using microencapsulated bromodichloromethane. The test substance was administered in the diet at doses of 0, 0.014, 0.055 and 0.22% for 24 months. Rats were sacrificed after 6, 12, 18 and 24 months of continuous dosing. The results showed a suppression of body weight gain in the 0.22% group for both males and females. Dose related changes were clearly observed in the liver with histopathological findings including fatty degeneration in the 0.014% or higher dose male groups, and fatty degeneration and granuloma in the 0.055 and 0.22% group females, as well as bile duct proliferation and cholangiofibrosis in the 0.22% group for both males and females. No significant differences in incidences or numbers of neoplastic changes were seen between control and any of the treatment groups. There were no dose-related non-neoplastic lesions in the kidneys of either sex. Lowest-observed-adverse-effect-level was determined to be 6.1 mg/kg/day under the present experimental conditions.
Aida
Y
Y
Division of Risk Assessment, National Institute of Hygienic Sciences, Tokyo, Japan.
Yasuhara
K
K
Takada
K
K
Kurokawa
Y
Y
Tobe
M
M
D000821:Animal Feed; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002214:Capsules; D004305:Dose-Response Relationship, Drug; D005260:Female; D006846:Hydrocarbons, Halogenated / Q000008:administration & dosage / Q000633:toxicity*; D007668:Kidney / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008111:Liver Function Tests; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D022882:Trihalomethanes
D002214:Capsules; D006846:Hydrocarbons, Halogenated; D022882:Trihalomethanes; C025191:bromodichloromethane