The Ussing chamber system for measuring intestinal permeability in health and disease.

BACKGROUND: The relationship between intestinal epithelial integrity and the development of intestinal disease is of increasing interest. A reduction in mucosal integrity has been associated with ulcerative colitis, Crohn's disease and potentially could have links with colorectal cancer development. The Ussing chamber system can be utilised as a valuable tool for measuring gut integrity. Here we describe step-by-step methodology required to measure intestinal permeability of both mouse and human colonic tissue samples ex vivo, using the latest equipment and software. This system can be modified to accommodate other tissues. METHODS: An Ussing chamber was constructed and adapted to support both mouse and human tissue to measure intestinal permeability, using paracellular flux and electrical measurements. Two mouse models of intestinal inflammation (dextran sodium sulphate treatment and T regulatory cell depletion using C57BL/6-FoxP3DTR mice) were used to validate the system along with human colonic biopsy samples. RESULTS: Distinct regional differences in permeability were consistently identified within mouse and healthy human colon. In particular, mice showed increased permeability in the mid colonic region. In humans the left colon is more permeable than the right. Furthermore, inflammatory conditions induced chemically or due to autoimmunity reduced intestinal integrity, validating the use of the system. CONCLUSIONS: The Ussing chamber has been used for many years to measure barrier function. However, a clear and informative methods paper describing the setup of modern equipment and step-by-step procedure to measure mouse and human intestinal permeability isn't available. The Ussing chamber system methodology we describe provides such detail to guide investigation of gut integrity.

Fibrofatty Band-Associated Small Bowel Obstruction After Marathon Running.

We report a 57-year-old man who developed subacute small bowel obstruction after running a marathon. A fibrofatty band was identified restricting the terminal ileum upon subsequent imaging. Surgical division of the band resulted in complete resolution of the patient's symptoms. Fibrofatty bands are embryonic remnants of the vitellointestinal duct and have not previously been reported to cause small bowel obstruction at the terminal ileum. We discuss the origin of remnant fibrofatty bands and physiological impact of running a marathon upon the gastrointestinal tract that would have contributed to development of subacute small bowel obstruction.