Biomaterial Database

Calcium and stimulus-secretion coupling in the mast cell: stimulant and inhibitory effects of calcium-rich media on exocytosis. 1977

W W Douglas, and M Kagayama

1. Isolated rat peritoneal mast cells incubated in Ca-free media for 2 h, with or without EDTA, and observed by phase-contact microscopy, became ;bubbled' in appearance when subsequently exposed to media rich in calcium (16-110 mM).2. Electron microscopy showed the response to be ;compound' exocytosis of the sort elicited by conventional mast cell secretagogues such as antigen (in sensitized cells) and 48/80.3. The response to Ca was inhibited by withdrawing glucose and adding dinitrophenol and was thus energy-dependent.4. Mg in similarly high concentration had no such stimulant effect on Ca-deprived cells, and excess Ca stimulated only after Ca deprivation.5. It is suggested that Ca deprivation may increase the permeability of the plasma membrane of the mast cell thereby allowing some Ca, when subsequently introduced in high concentration, to penetrate and activate exocytosis; and the results are considered further support for the postulated mediator function of Ca in stimulus-secretion coupling.6. Two inhibitory effects of calcium in high concentration were detected: (a) suppression of migration or expulsion of granules from the exocytotic pits within the cellular domain; and (b) diminished sensitivity to 48/80.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008297	Male		Males
D008407	Mast Cells	Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the BASOPHILS, mast cells contain large amounts of HISTAMINE and HEPARIN. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the STEM CELL FACTOR.	Basophils, Tissue,Basophil, Tissue,Cell, Mast,Cells, Mast,Mast Cell,Tissue Basophil,Tissue Basophils
D008858	Microscopy, Phase-Contrast	A form of interference microscopy in which variations of the refracting index in the object are converted into variations of intensity in the image. This is achieved by the action of a phase plate.	Phase-Contrast Microscopy,Microscopies, Phase-Contrast,Microscopy, Phase Contrast,Phase Contrast Microscopy,Phase-Contrast Microscopies
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D004140	Dinitrophenols	Organic compounds that contain two nitro groups attached to a phenol.
D005089	Exocytosis	Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia