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Mechanical removal of airway epithelium disrupts mast cells and releases granules
G M Franconi1, I Rubinstein, E H Levine
1Cardiovascular Research Institute, University of California, San Francisco 94143.
Abstract:
Many previous investigators have utilized mechanical rubbing as a method for examining effects of epithelial removal. In the present study, we examined whether this procedure also affects mast cell integrity in the underlying lamina propria. We isolated bronchial rings from six ferrets, and we found that removal of epithelium by rubbing decreased the total number of intact mast cells from 10.0 +/- 1.9 to 2.2 +/- 0.6 (SE) mast cells/mm luminal perimeter (P less than 0.01). In addition, we found a very large number of metachromatic particles that appeared to be mast cell granules unassociated with identifiable mast cells. Their identity was confirmed the presence of free mast cell granules and showed that they contained intact membranes. These effects were not observed when the epithelium was removed by enzymatic digestion, but they were observed after mechanical deformation of the bronchi alone. We suggest that mast cell components released by removing or damaging the epithelium may affect the function of various cells in the airway.
Insights
Mechanical rubbing to remove airway epithelium significantly damages mast cells, releasing their components. This finding is crucial for understanding airway inflammation and drug delivery research.
Area of Science:
- Respiratory physiology
- Cell biology
- Immunology
Background:
- Mechanical rubbing is a common method for epithelial removal in research.
- The impact of this method on underlying mast cells is not well understood.
Purpose of the Study:
- To investigate the effect of mechanical rubbing on mast cell integrity in ferret bronchi.
- To determine if mast cell degranulation occurs during epithelial removal by rubbing.
Main Methods:
- Bronchial rings were isolated from ferrets.
- Epithelium was removed using mechanical rubbing and enzymatic digestion.
- Mast cell integrity and granule release were assessed morphologically.
Main Results:
- Mechanical rubbing drastically reduced intact mast cells (10.0 to 2.2 cells/mm).
- Numerous free mast cell granules with intact membranes were observed after rubbing.
- Enzymatic digestion did not cause significant mast cell damage.
Conclusions:
- Mechanical rubbing, not just epithelial removal, damages mast cells and releases their components.
- Released mast cell mediators may influence airway cell function.
- This highlights potential confounds in studies using mechanical epithelial abrasion.