The effect of okadaic acid on histamine release, cell morphology and phosphorylation in rat basophilic leukemia (RBL-2H3) cells, human basophils and rat peritoneal mast cells.
To study the involvement of serine/threonine phosphatase in the signal transduction of mast cells, we examined the effects of okadaic acid (OA), an inhibitor of type-1 and -2A phosphatase on histamine release, cell morphology, calcium influx and protein phosphorylation of rat basophilic leukemia (RBL-2H3) cells, human basophils and rat peritoneal mast cells. OA inhibited IgE-mediated histamine release from RBL-2H3 cells and human basophils dose-dependently. There was a remarkable enhancement of IgE-mediated histamine release when rat peritoneal mast cells were suboptimally challenged. OA induced a marked change of cell features, detached RBL-2H3 cells from plastic well and kept the 18- and 68-kD proteins phosphorylated. These findings show that phosphatase may play a role in the modulation of secretion in mast cells.
Kitani
S
S
Department of Internal Medicine and Physical Therapy, University of Tokyo, Japan.
Teshima
R
R
Nonomura
Y
Y
Morita
Y
Y
Ito
K
K
D000818:Animals; D001491:Basophils / Q000166:cytology* / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D004988:Ethers, Cyclic / Q000494:pharmacology*; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007073:Immunoglobulin E / Q000494:pharmacology; D015471:Leukemia, Basophilic, Acute / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism; D019319:Okadaic Acid; D010529:Peritoneal Cavity / Q000166:cytology; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014407:Tumor Cells, Cultured
D004988:Ethers, Cyclic; D019319:Okadaic Acid; D007073:Immunoglobulin E; D017346:Protein Serine-Threonine Kinases; D002118:Calcium