Intrinsic factor-like activity in extracts of guinea pig intestine

Abstract

Co⁵⁷-labeled B₁₂ tube fed to guinea pigs with normal human gastric juice has been found in both the supernatant and sediment of a saline extract of intestinal mucosa. The Co⁵⁷-labeled material in the supernatant was excluded from Sephadex G-25, was not ultrafiltrable, and functioned as an intrinsic factor-B₁₂-Co⁵⁷ complex in an in vitro assay for intrinsic factor activity.