A CONTINUOUS AUTOMATED-METHOD FOR THE DETERMINATION OF INTESTINAL DISACCHARIDASE ACTIVITIES

A reliable method for the measurement of various disaccharidase activi ties such as maltase, isomaltase and sucrase is introduced. It is base d on the continuous measurement of liberated glucose by a commercially available glucose dehydrogenase reagent. The procedures were first op timized for enzymes from rat intestinal mucosa. The pH optima were sim ilar (6.3-6.7) for the three enzymes tested, and the apparent K(m)s we re estimated to be 18, 12 and 19 mmol/l for maltase, isomaltase and su crase, respectively. The procedures were adapted on a Cobas Mira autom ated analyzer. The assays correlated strongly with the conventional me thod of Dahlqvist. They were reliable, rapid, easy to perform and vali date because the progress curve of each reaction rate can be continuou sly monitored. The method described has also been applied to human int estinal mucosa (Caco-2 cells).