The behaviour of different markers of the mucosal extracellular space in rat small intestine.

The mucosal extracellular space in rat small intestine is determined with inulin-14C, mannitol-14C and unlabeled 2-deoxy-D-glucose in control animals and after an intravenous secretin load. The mannitol and 2-deoxy-D-glucose spaces in control animals are significantly greater than the inulin space. After secretin the three investigated markers show different, in part adverse, alterations of the mucosal extracellular space. These different results may be due to the composition of the incubation medium and to a distinct effect of secretin on the distribution of the employed markers.