Biomaterial Database

Effects of potassium and chloride on the membrane potentials of P815 mastocytoma tumor cells. 1982

D Geduldig, and D Jayasinghe, and D Lamb, and R March

The steady-state transmembrane potentials of P815 mastocytoma cells were recorded when the cells were bathed in salines of different compositions. In the normal growth medium (RPMI 1640 with added fetal calf serum) the mean membrane potential was -8.7 mV (SEM +/- 0.4, n = 22). A family of Tris-buffered salines (TBS), modeled from Dulbecco's modified PBS (289 mosmol, 169 milliionic strength units, pH 7.5), having different K+ and different C1- concentrations, were designed and used to bathe the tumor cells. All of the TBS solutions had constant, but reduced levels of ionized Ca2+. In the absence of external C1-, an increase of external K+ from 2 to 20 mM results in a 5.7 mV depolarization. In the presence of external C1- the same increase in external K+ results in a 2.1 mV depolarization. The presence of 145 mM C1- resulted in a steady-state depolarization (for either level of K) of about 50%. One explanation for these results would be the presence of an inward-going active C1- transport.

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012515	Mast-Cell Sarcoma	A unifocal malignant tumor that consists of atypical pathological MAST CELLS without systemic involvement. It causes local destructive growth in organs other than in skin or bone marrow.	Mastocytoma, Malignant,Sarcoma, Mast-Cell,Malignant Mastocytoma,Malignant Mastocytomas,Mast Cell Sarcoma,Mast-Cell Sarcomas,Mastocytomas, Malignant,Sarcoma, Mast Cell,Sarcomas, Mast-Cell