Long term bile collection in the rat.

Bile was collected from the rat continuously, over an extended period, using an externalized cannula brought through an intrascapular incision. The cannula was protected by a 30-cm, 16-gauge stainless steel tube attached to the skin through the incision. The rat was housed in a 10.2 x 10.2 x 12.7 cm cage at a lever higher than the collection vial to aid in drainage of bile. A hole in the vial cap permitted the cannula to turn freely as the rat moved about the cage. This method allowed bile to be collected conveniently over long periods of time with minimal restraint of the animal.