Tumor necrosis factor alpha immunoreactivity of rat peritoneal mast cell granules decreases during early secretion induced by compound 48/80: an ultrastructural immunogold morphometric analysis.
We used fast (seconds) and ultrafast (milliseconds) microwave energy-assisted chemical fixation protocols, postembedding immunogold staining, and a morphometric analysis to investigate the early morphological changes and the TNF-alpha immunoreactivity in the cytoplasmic granules of rat peritoneal mast cells that had been stimulated to secrete by exposure to compound 48/80. Exposure to compound 48/80 induced the development of increased numbers of cytoplasmic granules that exhibited decreased electron density; these granules often also appeared swollen. These granule alterations were accompanied by a significantly decreased proportion of granules that were positive for TNF-alpha immunoreactivity. We also calculated the density of TNF-alpha labeling/mu 2 in both dense (unaltered) and altered granules in specimens. TNF-alpha immunoreactivity was present in dense granules (regardless of whether or not the specimens had been stimulated with compound 48/80) and in cells that were fixed with either fast or ultrafast microwave energy. However, altered granules exhibited a decreased density of TNF-alpha label. These findings show that changes in the immunolocalization and/or density of TNF-alpha immunoreactivity occur very rapidly upon stimulation of rat peritoneal mast cells with compound 48/80.
Beil
W J
WJ
Department of Pathology, Beth Israel Hospital, Boston, Mass., USA.
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G R
GR
Aoki
M
M
Lunardi
L O
LO
Morgan
E S
ES
Galli
S J
SJ
Dvorak
A M
AM
D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D010529:Peritoneal Cavity / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D014409:Tumor Necrosis Factor-alpha; D003189:p-Methoxy-N-methylphenethylamine