Intestinal Absorption — Aspects of Structure, Function and Disease of the Small-Intestine Mucosa

Abstract

The Absorptive Process — Sugars, Lipids, Amino Acids and Vitamin B₁₂ To study absorption, two different approaches have been used. In vivo methods, such as measuring the disappearance of a test substance from the gut, its appearance in body fluids or its fecal output, tend to yield over-all results determined by a number of metabolic processes of which absorption is only one. If excised intestinal tissue is studied in vitro as a whole segment, discrete absorptive activities may be delineated, and if it is studied as a homogenate, biochemical pathways may be analyzed, but the unnatural experimental conditions must . . .