Zinc and copper in rat bile and pancreatic fluid: effects of surgery

The control of Zn and Cu homeostasis in the gut is not well understood; a role for bile and pancreatic secretions has been suggested. In the present study, the changes in biliary and pancreatic Zn and Cu after surgery were followed. Rats were prepared surgically with pancreatic, biliary, and intestinal cannulae, placed in restraint cages, and allowed to recover from anesthesia. Fluids were collected for up to 120 hours. Aliquots of the collected samples were analyzed for Zn and Cu. Zn in pancreatic juice did not follow a consistent pattern; however, the concentration of Zn was well correlated with pancreatic protein concentration. Cu in pancreatic juice was very low and was apparently not affected by surgery. In bile, Zn concentration increased markedly at about 40 hours postsurgery but declined to its initial level by days 4-5. Cu concentration in bile was similar to that of Zn initially, then increased 10-fold after 20-30 hours postsurgery, and returned to the initial level by days 4-5. These results demonstrate that the surgical procedure of cannulating bile and pancreatic ducts has a pronounced effect on the concentrations of Zn and Cu in bile and pancreatic fluid. This effect must be considered when designing and evaluating experiments concerned with the role of these secretions in trace element homeostasis.