Biomaterial Database

Voltage-sensitive calcium channels in differentiated neuroblastoma X glioma hybrid (NG108-15) cells: characterization by quin 2 fluorescence. 1988

L Noronha-Blob, and C Richard, and D C U'Prichard

Nova Pharmaceutical Corporation, Baltimore, Maryland 21224.

Depolarization of differentiated neuroblastoma X glioma (NG108-15) cells with KCl (50 mM) or veratridine (50 microM) stimulated Ca2+ accumulation, was detected by quin 2 fluorescence. Intracellular Ca2+ concentrations ([Ca2+]i) were elevated about threefold from 159 +/- 7 to 595 +/- 52 nM (n = 12). Ca2+ entry evoked by high extracellular K+ concentration ([K+]o) was voltage-dependent and enhanced by the dihydropyridine agonists, BAY K 8644 and CGP 28 392, in a dose-dependent manner. CGP 28 392 was less potent and less efficacious than BAY K 8644. The (+) and (-) stereoisomers of 202-791 showed agonist and antagonist properties, respectively. (+)-202-791 was less potent, but as efficacious as BAY K 8644. In the absence of KCl, BAY K 8644 had no effect on Ca2+ entry. Voltage-sensitive calcium channel (VSCC) activity was blocked by organic Ca2+ channel antagonists (nanomolar range) both before and after KCl treatment and also by divalent metal cations (micromolar range). High [K+]o-induced Ca2+ accumulation was dependent on external Ca2+, but not on external Na+ ions ([Na]o), and was insensitive to both tetrodotoxin (3 microM) and tetraethylammonium (10 microM). In contrast, veratridine-induced Ca2+ accumulation required [Na+]o, and was blocked by tetrodotoxin, but not by nimodipine (1 microM). Veratridine-induced Ca2+ accumulation was slower (approximately 45 s), smaller in magnitude (approximately 30% of [K+]o-induced Ca2+ entry), and also enhanced by BAY K 8644 (approximately 50%). VSCC were identified in neuronal hybrid (NG108-15 and NCB-20) cells, but not in glial (C6BU-1), renal epithelial (MDCK), and human astrocytoma (1321N1) cells. NG108-15 cells differentiated with 1.0 mM dibutyryl cyclic AMP showed greater VSCC activity than undifferentiated cultures. These results suggest that cultured neural cells provide a useful system to study Ca2+ regulation via ion channels.

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
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
D009447	Neuroblastoma	A common neoplasm of early childhood arising from neural crest cells in the sympathetic nervous system, and characterized by diverse clinical behavior, ranging from spontaneous remission to rapid metastatic progression and death. This tumor is the most common intraabdominal malignancy of childhood, but it may also arise from thorax, neck, or rarely occur in the central nervous system. Histologic features include uniform round cells with hyperchromatic nuclei arranged in nests and separated by fibrovascular septa. Neuroblastomas may be associated with the opsoclonus-myoclonus syndrome. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2099-2101; Curr Opin Oncol 1998 Jan;10(1):43-51)	Neuroblastomas
D011189	Potassium Chloride	A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.	Slow-K,Chloride, Potassium
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
D003994	Bucladesine	A cyclic nucleotide derivative that mimics the action of endogenous CYCLIC AMP and is capable of permeating the cell membrane. It has vasodilator properties and is used as a cardiac stimulant. (From Merck Index, 11th ed)	Dibutyryl Adenosine-3',5'-Monophosphate,Dibutyryl Cyclic AMP,(But)(2) cAMP,Bucladesine, Barium (1:1) Salt,Bucladesine, Disodium Salt,Bucladesine, Monosodium Salt,Bucladesine, Sodium Salt,DBcAMP,Dibutyryl Adenosine 3,5 Monophosphate,N',O'-Dibutyryl-cAMP,N(6),0(2')-Dibutyryl Cyclic AMP,AMP, Dibutyryl Cyclic,Adenosine-3',5'-Monophosphate, Dibutyryl,Cyclic AMP, Dibutyryl,Dibutyryl Adenosine 3',5' Monophosphate,Disodium Salt Bucladesine,Monosodium Salt Bucladesine,N',O' Dibutyryl cAMP,Sodium Salt Bucladesine
D004095	Dihydropyridines	Pyridine moieties which are partially saturated by the addition of two hydrogen atoms in any position.
D005456	Fluorescent Dyes	Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.	Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D005910	Glioma	Benign and malignant central nervous system neoplasms derived from glial cells (i.e., astrocytes, oligodendrocytes, and ependymocytes). Astrocytes may give rise to astrocytomas (ASTROCYTOMA) or glioblastoma multiforme (see GLIOBLASTOMA). Oligodendrocytes give rise to oligodendrogliomas (OLIGODENDROGLIOMA) and ependymocytes may undergo transformation to become EPENDYMOMA; CHOROID PLEXUS NEOPLASMS; or colloid cysts of the third ventricle. (From Escourolle et al., Manual of Basic Neuropathology, 2nd ed, p21)	Glial Cell Tumors,Malignant Glioma,Mixed Glioma,Glial Cell Tumor,Glioma, Malignant,Glioma, Mixed,Gliomas,Gliomas, Malignant,Gliomas, Mixed,Malignant Gliomas,Mixed Gliomas,Tumor, Glial Cell,Tumors, Glial Cell
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster