Intestinal permeability and faecal Granulocyte Marker Protein in Dextran Sulphate Sodium - induced colitis in rats
The aims of this preliminary study were to foster the development of an animal model of inflammatory bowel disease (IBD). We hereby studied the effects of dextran sulphate sodium (DSS) in drinking water on (a) intestinal permeability and (b) faecal levels of granulocyte marker protein (GMP) in rats. Methods were adopted to keep stress at a minimum. The animals had free access to DSS for 36 or 96 hrs. Controls received only water. Oral administration of 51Cr-labelled ethylenediaminetetraacetic acid (51CrEDTA) is used for clinical evaluation of intestinal permeability in IBD. 51CrEDTA was administered by training the animals to drink a given quantity of fluid within 5 minutes in a specific environment. On the test day, they voluntarily consumed 1 ml water containing 2 μCi 51CrEDTA. Urine samples were taken from filter paper in their home-cages for 6 hrs and radioactivity measured in a gamma counter. Faecal samples were collected after 36 and 96 hrs on DSS or water for GMP analysis. RESULTS: GMP was elevated in the DSSinduced animals after both 36 hrs (p<.05) and 96 hrs (p<.01), the elevation being greater after 96 hrs. Consumption of DSS increased the urinary excretion of 51CrEDTA after 36 hrs, but not after 96 hrs. Only DSS consumption for 96 hrs resulted in visible colonic erosions in either the proximal, mid or distal part of the colon. CONCLUSION: DSS has an acute effect upon urinary excretion of 51CrEDTA, and 96 hrs of access to DSS is sufficient to induce elevated GMP levels and colonic erosions in adult rats.