Biomaterial Database

Effect of hyperthermia on transmembrane potential of HeLa cells--a flow cytometric analysis. 1998

P Remani, and V Ostapenko, and K Akagi, and Y Tanaka

Division of Cancer Research, Regional Cancer Centre, Thiruvananthapuram, India.

The effect of hyperthermia on transmembrane potential was studied in HeLa cells in vitro using a 3',3'-dipentyl oxacarbocyanine [Di-0-C5(3)], a lipophilic cation probe that equilibrates across the plasma membrane according to the transmembrane potential. Uptake of the fluorescent probe was measured by flow cytometry. The flourescent intensity (FI) increased with increase in temperature, and the increase was statistically significant when the duration of heat treatment was 30 minutes or more. At each temperature studied the depolarization was higher after longer duration of heat treatment (p value: 41 degrees C < 0.05; 42 degrees C < 0.005; 43 degrees C < 0.001 and 44 degrees C < 0.001, respectively). The lack of significant depolarization after shorter duration of heating, particularly at lower temperatures could be due to the repair of membrane damage that could have occurred in the holding interval between heating and measurement. The results suggest that depolarization of membrane potential, i.e. increase in the intracellular cation concentration, can be considered as an indicator of cell injury by hyperthermia and may be mechanistically related to cell death by heat treatment. The technique may be suitable for studying repair of damage after hyperthermia.

UI	MeSH Term	Description	Entries
D006979	Hyperthermia, Induced	Abnormally high temperature intentionally induced in living things regionally or whole body. It is most often induced by radiation (heat waves, infra-red), ultrasound, or drugs.	Fever Therapy,Hyperthermia, Local,Hyperthermia, Therapeutic,Thermotherapy,Induced Hyperthermia,Therapeutic Hyperthermia,Therapy, Fever,Local Hyperthermia
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
D005434	Flow Cytometry	Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.	Cytofluorometry, Flow,Cytometry, Flow,Flow Microfluorimetry,Fluorescence-Activated Cell Sorting,Microfluorometry, Flow,Cell Sorting, Fluorescence-Activated,Cell Sortings, Fluorescence-Activated,Cytofluorometries, Flow,Cytometries, Flow,Flow Cytofluorometries,Flow Cytofluorometry,Flow Cytometries,Flow Microfluorometries,Flow Microfluorometry,Fluorescence Activated Cell Sorting,Fluorescence-Activated Cell Sortings,Microfluorimetry, Flow,Microfluorometries, Flow,Sorting, Fluorescence-Activated Cell,Sortings, Fluorescence-Activated Cell
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man