Biomaterial Database

Increased cytosolic pH in multidrug-resistant human lung tumor cells: effect of verapamil. 1989

H G Keizer, and H Joenje

Department of Toxicology, Duphar B.V., Weesp, The Netherlands.

In a set of four increasingly multidrug-resistant variants of SW-1573 human lung tumor cells, the pHi (i.e., steady-state cytosolic pH) increased up to 0.44 U as a function of the level of doxorubicin resistance. The elevated pHi in the most resistant (2,000-fold) variant dropped to the control level upon addition of verapamil, a known inhibitor of P-glycoprotein activity. These data suggest that, in the absence of xenobiotic substrates, P-glycoprotein activity can affect cellular pHi. This finding may be important for the elucidation of the physiological function of this protein.

UI	MeSH Term	Description	Entries
D008175	Lung Neoplasms	Tumors or cancer of the LUNG.	Cancer of Lung,Lung Cancer,Pulmonary Cancer,Pulmonary Neoplasms,Cancer of the Lung,Neoplasms, Lung,Neoplasms, Pulmonary,Cancer, Lung,Cancer, Pulmonary,Cancers, Lung,Cancers, Pulmonary,Lung Cancers,Lung Neoplasm,Neoplasm, Lung,Neoplasm, Pulmonary,Pulmonary Cancers,Pulmonary Neoplasm
D008562	Membrane Glycoproteins	Glycoproteins found on the membrane or surface of cells.	Cell Surface Glycoproteins,Surface Glycoproteins,Cell Surface Glycoprotein,Membrane Glycoprotein,Surface Glycoprotein,Glycoprotein, Cell Surface,Glycoprotein, Membrane,Glycoprotein, Surface,Glycoproteins, Cell Surface,Glycoproteins, Membrane,Glycoproteins, Surface,Surface Glycoprotein, Cell,Surface Glycoproteins, Cell
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D004317	Doxorubicin	Antineoplastic antibiotic obtained from Streptomyces peucetius. It is a hydroxy derivative of DAUNORUBICIN.	Adriamycin,Adriablastin,Adriablastine,Adriblastin,Adriblastina,Adriblastine,Adrimedac,DOXO-cell,Doxolem,Doxorubicin Hexal,Doxorubicin Hydrochloride,Doxorubicin NC,Doxorubicina Ferrer Farm,Doxorubicina Funk,Doxorubicina Tedec,Doxorubicine Baxter,Doxotec,Farmiblastina,Myocet,Onkodox,Ribodoxo,Rubex,Urokit Doxo-cell,DOXO cell,Hydrochloride, Doxorubicin,Urokit Doxo cell
D004351	Drug Resistance	Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.	Resistance, Drug
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D013755	Tetradecanoylphorbol Acetate	A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA.	Phorbol Myristate Acetate,12-Myristoyl-13-acetylphorbol,12-O-Tetradecanoyl Phorbol 13-Acetate,Tetradecanoylphorbol Acetate, 4a alpha-Isomer,12 Myristoyl 13 acetylphorbol,12 O Tetradecanoyl Phorbol 13 Acetate,13-Acetate, 12-O-Tetradecanoyl Phorbol,Acetate, Phorbol Myristate,Acetate, Tetradecanoylphorbol,Myristate Acetate, Phorbol,Phorbol 13-Acetate, 12-O-Tetradecanoyl,Tetradecanoylphorbol Acetate, 4a alpha Isomer
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured