[Mechanisms of glucose absorption at a high carbohydrate level in the rat small intestine in vivo].

At low maltose concentations, the rates of maltose hydrolysis and glucose absorption increased with increasing substrate concentration in the infusate. A significant fluid secretion occurred in the isolated intestinal loop perfused with hypertonic maltose solution, but water fluxes were close to zero in case of almost isotonic perfusion solutions. The findings suggest that the active transport remains a main mechanism of glucose absorption at super-high maltose concentration as well. The rates of maltose hydrolysis and released glucose absorption in the isolated intestinal loops perfused with super-high maltose concentration, enhance mainly due to an increase of effective digestive-absorptive surface of the villi and, in part, to substrate diffusion across the intestinal epithelium rather than paracellular solvent drag.