Mechanisms of increased intestinal [51Cr]EDTA absorption during experimental colitis in the rat

Experimental colitis was induced in the rat, by ethanol-oxazolone injections into the distal colon, resulting in diarrhea together with edema, ulcers, and cell infiltration in the exposed colon. Colitic rats showed an elevated urinary recovery of the permeability marker [⁵¹Cr]EDTA after intragastric feeding, 19±10%, compared to 2.9±0.7% for control rats (P<0.001). An increased retention of [⁵¹Cr]EDTA in the intestines and a decreased discharge in feces suggested an increased intestinal transit time in colitic rats. Thein vitro permeability to [⁵¹Cr]EDTA and ovalbumin was not elevated in the severely inflamed distal colon, but was in the proximal, unaffected colon to ovalbumin (P<0.05) and in the distal small intestine, to both [⁵¹Cr]EDTA (P<0.01) and ovalbumin (P<0.05), indicating that an inflammation in one part of the intestine could have permeability effects in other remote parts. In conclusion, the increased [⁵¹Cr]EDTA absorptionin vivo during colitis was probably due to both an increased permeability and an increased intestinal transit time.This study was supported by grants from The Swedish Natural Sciences Research Council and Astra Draco AB.