Mast cell degranulation and parenchymal cell injury in the rat mesentery.
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.
Costa
J J
JJ
Institute for Biomedical Engineering and Department of Bioengineering, University of California, San Diego, La Jolla 92093-0412, USA.
Harris
A G
AG
Delano
F A
FA
Zweifach
B W
BW
Schmid-Schönbein
G W
GW
D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects; D004727:Endothelium / Q000166:cytology; D007665:Ketotifen / Q000494:pharmacology; D007970:Leukopenia / Q000139:chemically induced; D008297:Male; D008407:Mast Cells / Q000166:cytology*; D008643:Mesentery / Q000166:cytology* / Q000293:injuries*; D011419:Propidium; D051381:Rats; D017208:Rats, Wistar; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D011419:Propidium; D003189:p-Methoxy-N-methylphenethylamine; D007665:Ketotifen