The system design has been updated to accommodate multiple chambers as shown in Fig. The Ussing system offers an ex vivo measurement of permeability using fluorescent probes as well as electrophysiological measurements. By monitoring ionic movements it was shown that Cl − secretion was decreased in patients, due to a mutated CFTR gene. In later years, the Ussing system helped unravel the mechanistic processes underpinning cystic fibrosis (CF). Such seminal studies paved the way for the present models of transepithelial transport, including the discovery of the Na +/K + ATPase pump. The eponymously named Ussing chamber takes its name from Danish biologist Hans Ussing, who developed the technique in the 1950s to understand the phenomenon of active Na + transport. Additionally, external factors including gastrointestinal motility and mucosal blood flow may lead to inaccuracy of permeability measurements. Whilst this method can determine overall differences in permeability between the small and large intestine, it is unable to reveal detailed information relating to precise regional locations of altered integrity within each organ and also lacks standardisation. Gut integrity can be assessed in vivo, by measuring the presence of molecular probes such as sugars or dextran in urine or blood after oral intake. Impairment of barrier function has been linked to intestinal diseases such as ulcerative colitis and Crohn’s disease. It is composed of epithelial cells, linked together by tight junctional (TJ) protein complexes, required for sealing the paracellular space. The intestinal epithelial barrier separates luminal contents from the internal body, crucial for maintaining the symbiotic relationship between the host and intestinal microbes. The Ussing chamber system methodology we describe provides such detail to guide investigation of gut integrity. 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 has been used for many years to measure barrier function. Furthermore, inflammatory conditions induced chemically or due to autoimmunity reduced intestinal integrity, validating the use of the system. In humans the left colon is more permeable than the right. In particular, mice showed increased permeability in the mid colonic region. Resultsĭistinct regional differences in permeability were consistently identified within mouse and healthy human colon. Two mouse models of intestinal inflammation (dextran sodium sulphate treatment and T regulatory cell depletion using C57BL/6-FoxP3 DTR mice) were used to validate the system along with human colonic biopsy samples. MethodsĪn Ussing chamber was constructed and adapted to support both mouse and human tissue to measure intestinal permeability, using paracellular flux and electrical measurements. This system can be modified to accommodate other tissues. 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. The Ussing chamber system can be utilised as a valuable tool for measuring gut integrity. A reduction in mucosal integrity has been associated with ulcerative colitis, Crohn’s disease and potentially could have links with colorectal cancer development. The relationship between intestinal epithelial integrity and the development of intestinal disease is of increasing interest.
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