The excretion of intravenously injected labeled zinc into pancreatic juice, duodenal juice, and bile of the dog was investigated. The use of the radioactive isotope permitted the injection of minute amounts of zinc, amounts that were negligible when compared with the total amount of zinc already present in the animal.
1. A large proportion of the injected Zn65 was eliminated by way of the external secretion of the pancreas. As much as 11 per cent was excreted in the pancreatic juice in 14 days.
2. Very little of the administered radiozinc appeared in the bile. The maximum excretion observed for this pathway was 0.4 per cent in 8 days.
3. Radiozinc was also found in large amounts in the juice obtained from an isolated loop of the duodenum.