Calcium mobilization by muscarinic receptors in human astrocytoma cells: Measurements with quin 2

Noronha-Blob, Lalita; Richard, C A; U’Prichard, David C.

doi:10.1016/s0006-291x(87)80104-3

Cited by 13 publications

(6 citation statements)

References 16 publications

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“…Glial cells respond to muscarinic stimulation with an increase in intracellular calcium levels. Although this effect had been previously observed in primary astrocytes and astrocytoma cells (11)(12)(13)(14)(15), these responses had not been well-characterized and quantitated. Intracellular calcium changes play an important role in many cellular functions, including proliferation, with the amplitude and frequency of the response determining the cellular response (21)(22)(23).…”

Section: Discussionmentioning

confidence: 86%

“…Additionally, PKC is activated by muscarinic stimulation of astrocytoma cells (9,10). There is also evidence that acetylcholine elevates intracellular calcium in mixed cortical cultures (8), primary astrocytes, and astrocytoma cells (11)(12)(13)(14)(15). Many of these studies, however, have looked at population responses or radioactive calcium release (6,(11)(12)(13), with only a limited number of studies assessing calcium signals in individual astroglia (14,15).…”

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confidence: 99%

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Muscarinic receptor‐induced calcium responses in astroglia

Catlin¹,

Kavanagh²,

Costa³

2000

Cytometry

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Background:The objective of this study was to characterize and quantitate the calcium responses to cholinergic stimulation in individual primary rat cortical astrocytes and human 132 1N1 astrocytoma cells. Materials and Methods:The fluorescent calcium probe Indo-1 AM and an attached cell analysis and sorting (ACAS) instrument were used to quantitate calcium responses in these cells. Results: A concentration-dependent response to carbachol was seen in both cell types. However, carbachol was more potent and efficacious, and the response was more homogeneous in the cell line. The calcium response was mediated by the M3 subtype of muscarinic receptors. Experiments in the absence of extracellular calcium and with EGTA demonstrated that the initial calcium spike

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Section: Discussionmentioning

confidence: 86%

mentioning

confidence: 99%

Muscarinic receptor‐induced calcium responses in astroglia

Catlin¹,

Kavanagh²,

Costa³

2000

Cytometry

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“…132 1 NI and MDCK cells were treated with trypsin (0.25% and 0.1% plus 30 pM EDTA, respectively) for 1-2 min at 37°C. Dispersed cells (5 x lo6 cclls/ml) were incubated with quin 2 acetoxymethyl ester (quin 2-AM) [ 100 pA4, in dimethyl sulfoxide (DMSO)] for 60 min at 37°C as described (Noronha-Blob et al, 1987). Control suspensions received only DMSO.…”

Section: Cell Culturementioning

confidence: 99%

Voltage‐Sensitive Calcium Channels in Differentiated Neuroblastoma × Glioma Hybrid (NG108–15) Cells: Characterization by Quin 2 Fluorescence

Noronha-Blob

Richard

U’Prichard

1988

Journal of Neurochemistry

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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.

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“…Glial cells respond to muscarinic stimulation with an increase in intracellular calcium levels. Although this effect had been previously observed in primary astrocytes and astrocytoma cells (11–15), these responses had not been well‐characterized and quantitated. Intracellular calcium changes play an important role in many cellular functions, including proliferation, with the amplitude and frequency of the response determining the cellular response (21–23).…”

Section: Discussionmentioning

confidence: 92%

“…Additionally, PKC is activated by muscarinic stimulation of astrocytoma cells (9, 10). There is also evidence that acetylcholine elevates intracellular calcium in mixed cortical cultures (8), primary astrocytes, and astrocytoma cells (11–15). Many of these studies, however, have looked at population responses or radioactive calcium release (6, 11–13), with only a limited number of studies assessing calcium signals in individual astroglia (14, 15).…”

mentioning

confidence: 99%

Muscarinic receptor-induced calcium responses in astroglia

2000

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Background The objective of this study was to characterize and quantitate the calcium responses to cholinergic stimulation in individual primary rat cortical astrocytes and human 132 1N1 astrocytoma cells. Materials and Methods The fluorescent calcium probe Indo‐1 AM and an attached cell analysis and sorting (ACAS) instrument were used to quantitate calcium responses in these cells. Results A concentration‐dependent response to carbachol was seen in both cell types. However, carbachol was more potent and efficacious, and the response was more homogeneous in the cell line. The calcium response was mediated by the M3 subtype of muscarinic receptors. Experiments in the absence of extracellular calcium and with EGTA demonstrated that the initial calcium spike was due to calcium release from intracellular calcium stores, whereas the sustained elevation and oscillations were dependent on calcium influx. Protein kinase C exerts a feedback inhibition of these calcium responses, and appears to be involved in maintaining the elevated calcium concentration and oscillations. Conclusions This study provided a detailed quantitation of the changes in intracellular calcium evoked in individual astroglial cells by activation of M3 muscarinic receptors. This will allow for the study of pharmacological and toxicological agents on this response. Cytometry 41:123–132, 2000 © 2000 Wiley‐Liss, Inc.

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Calcium mobilization by muscarinic receptors in human astrocytoma cells: Measurements with quin 2

Cited by 13 publications

References 16 publications

Muscarinic receptor‐induced calcium responses in astroglia

Muscarinic receptor‐induced calcium responses in astroglia

Voltage‐Sensitive Calcium Channels in Differentiated Neuroblastoma × Glioma Hybrid (NG108–15) Cells: Characterization by Quin 2 Fluorescence

Muscarinic receptor-induced calcium responses in astroglia

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