Effect of Intrinsic Factor Concentrates on Vitamin B 12 Receptor Protein of Tissues. ∗

Summary

Data have been presented which show that intrinsic factor containing materials will stimulate receptor proteins to combine Vit. B₁₂ of tissues as well as serum. Further, the receptor proteins of tissues are located intracellularly in the microsome and soluble protein fraction of liver homogenates. The evidence suggests that intrinsic factor aids in absorption of Vit. B₁₂ by stimulating the intracellular receptor proteins to combine with Vit. B₁₂.