Comparison of Polysucrose 15000,51Cr-labelled Ethylenediaminetetraacetic Acid, and14C-Mannitol as Markers of Intestinal Permeability in Man

We recently reported increased intestinal permeability to polysucrose (PS) 15000 in patients with Crohn's disease and in patients treated with non-steroidal anti-inflammatory drugs (NSAIDs). We have now compared this new macromolecular marker (14,700 D) with the conventional markers, 51Cr-labelled ethylenediaminetetraacetic acid (EDTA) (342 D) and 14C-mannitol (182 D), in healthy humans.Twenty healthy volunteers on four occasions ingested a solution containing PS 15000, 51Cr-EDTA, and 14C-mannitol, the test solution being, respectively, isoosmolar, hyperosmolar, isoosmolar followed by a standard meal, and isoosmolar after 1 week of NSAID treatment. Fractional urinary excretion of the substances was measured over 0-4 h, 4-8 h, and 8-12 h.The excretion of PS 15000 was, like that of 51Cr-EDTA but unlike that of 14C-mannitol, increased by NSAID pretreatment, little affected by hyperosmolar test solution, little correlated to urinary volume, and skew with regard to frequency distribution. Despite being nominally about 40 times lower, the excretion of PS 15000 was highly correlated to that of 51Cr-EDTA but not to that of 14C-mannitol. A standard meal reduced the test variability for all three probes.PS 15000 may be an alternative to 51Cr-EDTA as a small-intestinal permeability marker. Inclusion of a standard meal reduces test variability.