Biomaterial Database

Calcium regulation of the contractile state of isolated mammalian fibroblast cytoplasm. 1975

C S Izzard, and S L Izzard

Calcium-dependent contractions have been induced in fresh, naked cytoplasm of L-929 fibroblasts using physiological solutions (rigor, relaxing and contracting) similar to those designed to control the contractile state of vertebrate striated muscle. Free access of solutions to the cytoplasm was achieved by popping and stripping the plasma membrane from cells using 7-10 strokes of a Dounce homogenizer. Contracting solution (free Ca2+ 7 X 10(-5) M; with added MgATP) applied locally from a micropipette to cells popped in rigor (free Ca2+ less than 10(-8) M) or relaxing (free Ca2+ less than 10(-8) M; with added MgATP) solutions induced symmetrical contractions of unstretched cytoplasm and directional shortening of stretched cytoplasm. The contractions produced 12-18% shortenings and were complete in 1-3 s. The cytoplasm could be cycled repeatedly through the contracted state from the relaxed state. Exogenous MgATP was required for the Ca2+-dependent contractions. At low free Ca2+ concentrations (less than 10(-8) M), MgATP had a marked plasticizing effect on the cytoplasm. Thus cytoplasm prepared in relaxing solution was less cohesive and more easily deformed than cytoplasm prepared in rigor solution. When induced to contract, relaxed cytoplasm showed a loss of plasticity. Using this criterion, the threshold concentration of free Ca2+ for contraction was determined to lie between 7 X 10(-8) M and 5 X 10(-7) M.

UI	MeSH Term	Description	Entries
D007739	L Cells	A cultured line of C3H mouse FIBROBLASTS that do not adhere to one another and do not express CADHERINS.	Earle's Strain L Cells,L Cell Line,L Cells (Cell Line),L-Cell Line,L-Cells,L-Cells, Cell Line,L929 Cell Line,L929 Cells,NCTC Clone 929 Cells,NCTC Clone 929 of Strain L Cells,Strain L Cells,Cell Line L-Cell,Cell Line L-Cells,Cell Line, L,Cell Line, L929,Cell Lines, L,Cell, L,Cell, L (Cell Line),Cell, L929,Cell, Strain L,Cells, L,Cells, L (Cell Line),Cells, L929,Cells, Strain L,L Cell,L Cell (Cell Line),L Cell Lines,L Cell, Strain,L Cells, Cell Line,L Cells, Strain,L-Cell,L-Cell Lines,L-Cell, Cell Line,L929 Cell,Strain L Cell
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.
D008846	Micromanipulation	The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.	Micromanipulations
D008857	Microscopy, Interference	The science and application of a double-beam transmission interference microscope in which the illuminating light beam is split into two paths. One beam passes through the specimen while the other beam reflects off a reference mirror before joining and interfering with the other. The observed optical path difference between the two beams can be measured and used to discriminate minute differences in thickness and refraction of non-stained transparent specimens, such as living cells in culture.	Interferometry, Microscopic,Microinterferometry,Microscopy, Differential Interference Contrast,Microscopy, Interference Reflection,Microscopy, Nomarski Interference Contrast,Interference Microscopy,Interference Reflection Microscopy,Microscopic Interferometry,Reflection Microscopy, Interference
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
D002465	Cell Movement	The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.	Cell Migration,Locomotion, Cell,Migration, Cell,Motility, Cell,Movement, Cell,Cell Locomotion,Cell Motility,Cell Movements,Movements, Cell
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms
D003594	Cytoplasmic Granules	Condensed areas of cellular material that may be bounded by a membrane.	Cytoplasmic Granule,Granule, Cytoplasmic,Granules, Cytoplasmic
D004533	Egtazic Acid	A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.	EGTA,Ethylene Glycol Tetraacetic Acid,EGATA,Egtazic Acid Disodium Salt,Egtazic Acid Potassium Salt,Egtazic Acid Sodium Salt,Ethylene Glycol Bis(2-aminoethyl ether)tetraacetic Acid,Ethylenebis(oxyethylenenitrile)tetraacetic Acid,GEDTA,Glycoletherdiamine-N,N,N',N'-tetraacetic Acid,Magnesium-EGTA,Tetrasodium EGTA,Acid, Egtazic,EGTA, Tetrasodium,Magnesium EGTA
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2