Epithelial Permeability
Epithelial Permeability - Related Videos
06:37
An Assay for Permeability of the Zebrafish Embryonic Neuroepithelium
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Cited by 11 •
2012
We describe a live whole animal quantitative measurement for permeability of the embryonic zebrafish brain. The technique analyzes the ability to retain cerebrospinal fluid and molecules of different molecular weights within the neural tube lumen and quantifies their movement out of the ventricles. This method is useful for determining differences in epithelial permeability and maturation during development and disease.
07:51
Testing Epithelial Permeability in Fetal Tissue-Derived Enteroids
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Cited by 2 •
2022
This protocol details the establishment of enteroids, a three-dimensional intestinal model, from fetal intestinal tissue. Immunofluorescent imaging of epithelial biomarkers was used for model characterization. Apical exposure of lipopolysaccharides, a bacterial endotoxin, using microinjection technique induced epithelial permeability in a dose-dependent manner measured by the leakage of fluorescent dextran.
10:22
In Vitro and In Vivo Approaches to Determine Intestinal Epithelial Cell Permeability
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Cited by 44 •
2018
Two methods are presented here to determine intestinal barrier function. An epithelial meter (volt/ohm) is used for measurements of transepithelial electrical resistance of cultured epithelia directly in tissue culture wells. In mice, the FITC-dextran gavage method is used to determine the intestinal permeability in vivo.
08:04
Real-time Measurement of Epithelial Barrier Permeability in Human Intestinal Organoids
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Cited by 50 •
2017
This protocol describes the measurement of epithelial barrier permeability in real-time following pharmacologic treatment in human intestinal organoids using fluorescent microscopy and live cell microscopy.
02:45
Assessment of Intestinal Permeability in C. elegans Following Bacterial Exposure
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2026
Source: Le, T. A. N., et al., Measuring the Effects of Bacteria and Chemicals on the Intestinal Permeability of Caenorhabditis elegans. J. Vis. Exp. (2019)This video demonstrates a fluorescence-based assay to quantify intestinal permeability in C. elegans exposed to Pseudomonas aeruginosa. Compared to controls fed Escherichia coli, pathogen-treated worms show increased fluorophore leakage into the body cavity, indicating epithelial barrier damage.
FAQs
Epithelial permeability reflects two complementary routes rather than a single transport process. In the transcellular route, substances cross epithelial cell membranes; in the paracellular route, they pass between neighboring cells. Tight junctions regulate the latter, so comparing these routes helps explain how a tissue controls movement across its compartments.
Tight junctions act as selective controls at cell-cell boundaries. Their regulation can alter which molecules move through the paracellular pathway, with passage shaped by molecular size and charge. This matters because a change in junctional control can modify barrier selectivity without requiring every substance to cross cell membranes directly.
Barrier behavior cannot be inferred from one epithelial model alone. Tissue-specific structure influences how epithelial layers handle water, ions, nutrients, drugs, and other molecules. For this reason, comparisons among intestinal, vascular, renal, and respiratory epithelia can reveal why permeability measurements differ between body compartments and why model choice matters.
Changes in epithelial permeability can serve as an indicator of altered barrier function during inflammation or disease. Measuring those changes helps investigators determine whether movement between compartments has increased or otherwise shifted. The resulting information supports biological studies of tissue disruption and can connect barrier behavior with disease-related conditions.
Permeability measurements are used to characterize how an epithelial barrier handles selected classes of substances, including water, ions, nutrients, drugs, and other molecules. Interpreting the measurements in relation to the tissue being studied helps distinguish general barrier behavior from properties associated with intestinal, vascular, renal, or respiratory systems.
In drug research, epithelial permeability studies help evaluate how therapeutics cross epithelial tissues and support investigations of drug absorption. The same approach contributes to barrier models for biomedical research, where controlled epithelial systems can be examined to understand transport behavior and its relevance to tissue homeostasis.