Milk Transfer Study in Rats

For registration of a drug, data are required on excretion with the milk as well as data about the correlation between the blood and milk level. 

10 lactating healthy female Sprague-Dawley rats weighing about 300 g (approx. 13 weeks old) receive the radiolabeled compound the route of administration projected to be used therapeutically. For oral or intravenous administration to rats as well as details concerning animal maintenance see section Mass balance study in rats . 

For milking, the animals were held by the nape. A sucking pump17 was put alternately onto the individual teats to collect the withdrawn milk into an 

17can be easily constructed connecting a water-jet pump with a micro wash bottle an Eppendorf vessel is placed under the inlet tube at the other end the inlet tube is fitted with a polyethylene tube and a microfunnel. The micro wash bottle can be assembled from a 15-mL scintillation vessel with two openings in the lid and polyethylene tubing. 

In cases where the milking and blood sampling are very narrow at first, it is recommended to use two alternative groups of animals. 

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