Related Experiment Videos
Experimental colitis increases small intestine permeability in the rat
W Fries1, E Mazzon, S Squarzoni
1Gastroenterologia, Dip. to di Biomorfologia, Università di Messina, Italy.
Laboratory Investigation; a Journal of Technical Methods and Pathology
|February 10, 1999
Summary
Inflammation from colitis significantly increases small intestine permeability by disrupting occludin in tight junctions (TJ). This increased "leakiness" throughout the small intestine correlates with colon damage severity.
Area of Science:
- Gastroenterology
- Cell Biology
- Pathology
Background:
- Small intestine permeability alterations are implicated in Crohn's disease pathogenesis.
- Understanding tight junction (TJ) dysfunction is crucial for inflammatory bowel disease research.
Purpose of the Study:
- To investigate small intestine TJ structure and permeability in a chronic distal colitis animal model.
- To identify molecular changes in TJs associated with colitis.
Main Methods:
- Induction of chronic distal colitis using trinitrobenzenesulfonic acid/ethanol in rats.
- Transmission electron microscopy with lanthanum nitrate to assess TJ permeability.
- Freeze-fracture analysis and immunohistochemistry for occludin, ZO-1, and cingulin.
Main Results:
- Colitis significantly increased duodenal and ileal TJ permeability to lanthanum (79.5% and 72.9%, respectively).
- Increased TJ permeability correlated positively with macroscopic colon damage scores.
- Occludin protein showed disrupted and irregular signals in both small intestine segments, while ZO-1 and cingulin remained unchanged.
Conclusions:
- Distal colitis causes increased TJ permeability throughout the small intestine, linked to colon damage.
- Alterations in the transmembrane protein occludin appear to be the primary cause of observed TJ permeability changes.
- Further research is needed to understand how remote inflammation affects TJ integrity.