Related Experiment Video
Updated: Jul 24, 2026
07:22
Quantifying Single Microvessel Permeability in Isolated Blood-perfused Rat Lung Preparation
Published on: June 30, 2014
Study of airway epithelial permeability with dextran
W C Hulbert1, B B Forster, J G Mehta
1Department of Medicine, University of Alberta, Edmonton, Canada.
Journal of Electron Microscopy Technique
|February 1, 1989
Summary
Cigarette smoke exposure increases tracheal paracellular permeability. Fluorescein isothiocyanate (FITC) T-40 dextran effectively measures these major changes in guinea pig airways.
Area of Science:
- Respiratory Physiology
- Cell Biology
- Toxicology
Background:
- The integrity of the paracellular pathway in the tracheal mucosa is crucial for airway defense.
- Exposure to environmental irritants like cigarette smoke can compromise this barrier function.
Purpose of the Study:
- To investigate the effect of cigarette smoke exposure on tracheal paracellular permeability.
- To evaluate the utility of fluorescein isothiocyanate (FITC) T-40 dextran as a marker for assessing paracellular permeability.
Main Methods:
- Guinea pigs were exposed to cigarette smoke or room air (controls).
- FITC T-40 dextran was instilled into the trachea, and serial blood samples were collected.
- Tracheal tissues were examined using light and transmission electron microscopy.
Main Results:
- Dextran was detected in paracellular spaces of smoke-exposed tracheas but not in controls.
- Plasma dextran levels increased significantly in smoke-exposed animals, indicating systemic absorption.
- Control animals showed undetectable plasma dextran levels.
Conclusions:
- FITC T-40 dextran is a reliable method for detecting significant alterations in tracheal paracellular permeability.
- Cigarette smoke exposure markedly enhances paracellular permeability in the tracheal mucosa.
