The Estimation of Intrinsic Factor Using Guinea-Pig Intestinal Brush Borders

Abstract

Human gastric juice specifically enhanced the uptake of [⁵⁷Co] cyano-cobalamin by both homogenates and brush borders prepared from guinea-pig ileum. The uptake by the brush borders was much greater than the uptake by whole homogenates. Uptake was enhanced by rat and guinea-pig intrinsic factor but not by hog intrinsic factor or non-intrinsic factor vitamin B₁₂ binders. Uptake was also inhibited by both binding and blocking intrinsic factor antibodies. Guinea-pig brush borders may be used as a convenient highly specific assay of various intrinsic factor preparations or for the detection of intrinsic factor antibodies in sera and gastric juices.

Key-words:

• Intestinal absorption
• intrinsic factor
• mucous membranes
• vitamin B₁₂