A method for studies on milk excretion of chemicals in mice with 2,2 ',4,4 ',5-pentabromodiphenyl ether (BDE-99) as a model

A simple and rapid milking technique for mice is described by which multiple milk samples can be collected from anaesthetised dams after I h separation from the litter. Three samples of milk were collected from each dam by aspiration via a flexible tubing fitted to the nipple and approximately 0.3-0.5 ml milk was obtained at each time point. The milking technique was tested with 14 C-labelled 2,2',4,4,5-pentabromodiphenyl ether (BDE-99) as a model substance. A rapid and efficient milk excretion of BDE-99, with a milk/plasma ratio of approximately 40, was demonstrated. During the studied 7 days most of the given dose was excreted in milk with peak levels already 4-10 h after an intravenous administration. Higher tissue concentrations of BDE-99 were found in suckling neonates than in dams, probably due to a high dose per kilogram body weight from milk and an efficient absorption via the gastrointestinal tract in the pups. (C) 2004 Elsevier Ireland Ltd. All rights reserved.