Related Experiment Video
Updated: May 19, 2026

Functional Assessment of Intestinal Permeability and Neutrophil Transepithelial Migration in Mice using a Standardized Intestinal Loop Model
Published on: February 11, 2021
Intestinal permeability and its regulation by zonulin: diagnostic and therapeutic implications
1Mucosal Biology Research Center and Center for Celiac Research, University of Maryland School of Medicine, Baltimore, MD 21201, USA. afasano@mbrc.umaryland.edu
Abstract:
One of the most important and overlooked functions of the gastrointestinal tract is to provide a dynamic barrier to tightly controlled antigen trafficking through both the transcellular and paracellular pathways. Intercellular tight junctions (TJ) are the key structures regulating paracellular trafficking of macromolecules. Although steady progress has been made in understanding TJ ultrastructure, relatively little is known about their pathophysiological regulation. Our discovery of zonulin, the only known physiological modulator of intercellular TJ described so far, increased understanding of the intricate mechanisms that regulate gut permeability and led us to appreciate that its up-regulation in genetically susceptible individuals may lead to immune-mediated diseases. This information has translational implications, because the zonulin pathway is currently exploited to develop both diagnostic and therapeutic applications pertinent to a variety of immune-mediated diseases.
Related Concept Videos
Tight Junctions
Transcellular Transport of Solutes
Inflammatory Bowel Disease III: Diagnostic Studies and Management I-Nutritional Therapy
Diagnostic studies
A colonoscopy is the definitive screening test, distinguishing ulcerative colitis from other colon diseases with similar symptoms. During a colonoscopy test, inflamed mucosa with exudate ulcerations can be observed, and biopsies are taken to determine the histologic characteristics of the colonic...
Inflammatory Bowel Disease II: Ulcerative Colitis
Bioavailability Enhancement: Drug Permeability Enhancement
Irritable Bowel Syndrome