Effects of gastric juice fractions on uptake of labeled vitamin B12 by rat liver slices.

Summary1. Gastric contents from 2 subjects without pernicious anemia have been chromatographed on an IRC resin column. Five more or less well defined protein peaks appeared in the effluent. Each peak was capable of enhancing uptake of Co60 Vit. B12 by the rat liver slice. 2. Prior to fractionation and after these gastric fractions have been reconstituted, these gastric juices produced inhibition of Co60 Vit. B12 uptake by the rat liver slice at all concentrations tested. 3. The effluent of these chromatographic separations of human gastric content produced 3 Co60 Vit. B12 binding peaks. Destroying proteolytic activity of one of these gastric juices decreased the binding of one of these but did not change the results with the liver slice. 4. The enhanced uptake on the rat liver slice produced by these gastric juice fractions did not seem to be related to proteolytic activity.