Accurate assay of low intestinal lactase activity with a fluorometric method

✍ Scribed by Arne Dahlqvist; Nils-Georg Asp

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 201 KB
• Volume: 44
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(71)90256-9

✦ Synopsis

Assay of small-intestinal lactase activity in jejunal biopsies is usually performed with the Tris/glucose oxidase reagent of Dahlqvist

(1,2) or more or less modified methods. The glucose oxidase methods are simple and well suited for differentiation of the low activities in lactase-deficient individuals from the high activities in individuals with persistent lactase.

Accurate assay and characterization of the low residual lactase activity in lactase deficient individuals is of interest for the understanding of the biochemical alteration and genetic mechanism of different forms of human lactase deficiency. The high concentration of mucosal homogenate needed for assay of very low activities, however, tends to interfere with the glucose oxidase-peroxidase system (3)) making internal standards necessary.

The galactose dehydrogenase-NAD+ method now reported has the advantage of being five times more sensitive than the ultramioromodification (2) of the glucose oxidase method. The system is also not influenced even by high concentrations of mucosal homogenate in the incubation mixture. MATERIALS