Demonstration of a vitamin B12 binder in pancreatic juice. Effect on the intestinal uptake of vitamin B12.

Determination of vitamin-B12-binding capacity and gel filtration of human pancreatic juice (HPJ) and rat pancreatic juice (RPJ) demonstrated a vitamin B12 binder different from gastric intrinsic factor (IF). The results also indicated the presence of the pancreatic B12 binding in human duodenal juice. The binder in RPJ had no significant effect on the uptake of 57CoB12 and 57CoB12 bound to rat IF by perfused rat intestinal segments (p greater than 0.5; p greater than 0.1). The binder in HPJ had no effect on the uptake of unbound 57CoB12 or 57CoB12 bound to human IF by guinea pig intestinal brush borders (p greater than 0.05; p greater than 0.1). The results indicate that the pancreatic vitamin B12 binder does not influence the intestinal uptake of vitamin B12.