The role of intracellular Ca2+ in the degranulation of skinned mast cells.
The intracellular pH of rat peritoneal mast cells was slightly acidic and compound 48/80 induced a decrease in the cytoplasmic pH of these cells. By means of chemical skinning, it was revealed that perfusion with Ca2+ or inositol 1,4,5-trisphosphate (IP3) induced degranulation dose-dependently in mast cells at concentrations higher than 10 microM and 0.1 microM, respectively. Na+ was essential for the release of histamine from mast cells. An assay based on the binding of 45Ca to mast cell fragments revealed that the intracellular Ca store of the mast cell is located in the endoplasmic reticulum. IP3 liberated Ca from the endoplasmic reticulum.
D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D002462:Cell Membrane / Q000502:physiology; D003594:Cytoplasmic Granules / Q000502:physiology; D006636:Histamine Release / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology*; D008297:Male; D008407:Mast Cells / Q000502:physiology*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D009940:Organoids / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013403:Sugar Phosphates / Q000494:pharmacology*
D007295:Inositol Phosphates; D013403:Sugar Phosphates; D015544:Inositol 1,4,5-Trisphosphate; D009251:NADPH-Ferrihemoprotein Reductase; D002118:Calcium