In vitro inhibition of rat intestinal surface hydrolysis of disaccharides and dipeptides by guaran.

The effect of guaran on intestinal surface hydrolases was studied in everted jejunal segments by measuring the hydrolysis of maltose and phenylalanylglycine. On the basis of kinetic experiments, guaran was found to inhibit competitively the hydrolysis of these substrates only if the cleavage was performed with intact tissue. Hydrolysis in mucosal homogenates was not affected by guaran, indicating that this polysaccharide may increase the diffusion barrier overlaying the mucosa and thus may retard final digestion of carbohydrates and peptides.