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Rat Mesentery Exteriorization: A Model for Investigating the Cellular Dynamics Involved in Angiogenesis
Published on: May 20, 2012
Mast cell degranulation and parenchymal cell injury in the rat mesentery
J J Costa1, A G Harris, F A Delano
1Institute for Biomedical Engineering and Department of Bioengineering, University of California, San Diego, La Jolla 92093-0412, USA.
Objective:
The objective of this study was to explore the degree of parenchymal cell injury after mast cell degranulation by application of compound 48/80 (CMP 48/80) in the absence of adherent leukocytes in the rat mesentery.
Methods:
Rats were rendered leukopenic by injection of an antibody against leukocytes, and the mesentery was superfused with CMP 48/80 during intravital microscopy. The extent of cell injury was determined using a fluorescent cell-viability indicator, propidium iodide (PI). In an additional group, mast cell degranulation with CMP 48/80 was prevented by using the mast cell stabilizer Ketotifen.
Results:
After a reduction in the number of circulating leukocytes, mast cell degranulation produced a mild increase in parenchymal cell injury. The injury levels significantly increased when individual regions of the mesentery were compared. Stabilization of the mast cells with Ketotifen reduced the injury to below baseline values.
Conclusions:
In the absence of leukocyte adhesion to the endothelium, mast cell degranulation contributes to parenchymal cell injury in the mesentery.
Insights
Mast cell degranulation, triggered by compound 48/80 (CMP 48/80), causes mild parenchymal cell injury in rat mesentery even without leukocytes. Mast cell stabilization with Ketotifen prevented this injury.
Area of Science:
- Physiology
- Immunology
- Microcirculation
Background:
- Mast cells play a role in inflammatory responses.
- Leukocyte adhesion is a key event in inflammation.
- Parenchymal cell injury can result from inflammatory processes.
Purpose of the Study:
- To investigate mast cell degranulation's effect on parenchymal cell injury.
- To assess this injury in the absence of adherent leukocytes.
- To determine the role of mast cells in mesenteric injury.
Main Methods:
- Rats were made leukopenic using antibody treatment.
- Intravital microscopy was used to superfuse the mesentery with compound 48/80 (CMP 48/80).
- Propidium iodide (PI) assessed cell viability; Ketotifen stabilized mast cells.
Main Results:
- CMP 48/80 caused a mild increase in parenchymal cell injury after leukocyte reduction.
- Mesenteric injury levels significantly increased in specific regions.
- Ketotifen treatment reduced injury below baseline levels.
Conclusions:
- Mast cell degranulation contributes to mesenteric parenchymal cell injury.
- This occurs even when leukocyte adhesion to the endothelium is absent.
- Mast cells are implicated in direct tissue damage during inflammation.
