scholarly journals Simultaneous Measurements of Intracellular Calcium and Membrane Potential in Freshly Isolated and Intact Mouse Cerebral Endothelium

10.3791/58832 ◽  
2019 ◽  
Author(s):  
Md A. Hakim ◽  
Erik J. Behringer
Keyword(s):  
Membrane Potential ◽  
Intracellular Calcium ◽  
Cerebral Endothelium ◽  
Intact Mouse ◽  
Simultaneous Measurements

Regulation of intracellular calcium in N1E-115 neuroblastoma cells: the role of Na+/Ca2+exchange

2002 ◽  
Vol 282 (5) ◽  
pp. C1000-C1008 ◽  
Author(s):  
Kara L. Kopper ◽  
Joseph S. Adorante
Keyword(s):  
Membrane Potential ◽  
Intracellular Calcium ◽  
Normal Cell ◽  
Buffer Capacity ◽  
Neuroblastoma Cells ◽  
Fold Increase ◽  
Scorpion Venom ◽  
Reverse Mode ◽  
Intracellular Ca

In fura 2-loaded N1E-115 cells, regulation of intracellular Ca2+ concentration ([Ca2+]i) following a Ca2+ load induced by 1 μM thapsigargin and 10 μM carbonylcyanide p-trifluoromethyoxyphenylhydrazone (FCCP) was Na+ dependent and inhibited by 5 mM Ni2+. In cells with normal intracellular Na+ concentration ([Na+]i), removal of bath Na+, which should result in reversal of Na+/Ca2+exchange, did not increase [Ca2+]i unless cell Ca2+ buffer capacity was reduced. When N1E-115 cells were Na+ loaded using 100 μM veratridine and 4 μg/ml scorpion venom, the rate of the reverse mode of the Na+/Ca2+ exchanger was apparently enhanced, since an ∼4- to 6-fold increase in [Ca2+]ioccurred despite normal cell Ca2+ buffering. In SBFI-loaded cells, we were able to demonstrate forward operation of the Na+/Ca2+ exchanger (net efflux of Ca2+) by observing increases (∼ 6 mM) in [Na+]i. These Ni2+ (5 mM)-inhibited increases in [Na+]i could only be observed when a continuous ionomycin-induced influx of Ca2+ occurred. The voltage-sensitive dye bis-(1,3-diethylthiobarbituric acid) trimethine oxonol was used to measure changes in membrane potential. Ionomycin (1 μM) depolarized N1E-115 cells (∼25 mV). This depolarization was Na+dependent and blocked by 5 mM Ni2+ and 250–500 μM benzamil. These data provide evidence for the presence of an electrogenic Na+/Ca2+ exchanger that is capable of regulating [Ca2+]i after release of Ca2+ from cell stores.

scholarly journals Voltage-gated potassium channel Kv1.3 in rabbit ciliary epithelium regulates the membrane potential via coupling intracellular calcium

2008 ◽  
Vol 121 (22) ◽  
pp. 2272-2277 ◽  
Author(s):  
Yan-feng LI ◽  
Ye-hong ZHUO ◽  
Wei-na BI ◽  
Yu-jing BAI ◽  
Yan-na LI ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Potassium Channel ◽  
Intracellular Calcium ◽  
Ciliary Epithelium ◽  
Voltage Gated

Control of intracellular calcium by membrane potential in human melanoma cells

1993 ◽  
Vol 265 (6) ◽  
pp. C1501-C1510 ◽  
Author(s):  
B. Nilius ◽  
G. Schwarz ◽  
G. Droogmans
Keyword(s):  
Cell Proliferation ◽  
Membrane Potential ◽  
Intracellular Calcium ◽  
Reversal Potential ◽  
Melanoma Cells ◽  
Human Melanoma ◽  
Resting Potential ◽  
Equilibrium Potential ◽  
Patch Clamp Technique ◽  
Human Melanoma Cells

The modulation of intracellular calcium ([Ca2+]i) by the membrane potential was investigated in human melanoma cells by combining the nystatin-perforated patch-clamp technique with Ca2+ measurements. Voltage steps to -100 mV induced a rise in [Ca2+]i and a creeping inward current. These effects were absent in Ca(2+)-free solution and could be blocked by Ni2+ or La3+. Voltage ramps revealed a close correlation between [Ca2+]i and voltage, with the strongest voltage dependence around the resting potential. Long-lasting tail currents, closely correlated with the rise in [Ca2+]i and a reversal potential close to the K+ equilibrium potential, occurred if the membrane potential was clamped back to 0 mV. They were absent if intracellular K+ was replaced by Cs+ and blocked by extracellular tetraethylammonium (5 mM), Ba2+ (1 mM), or a membrane-permeable adenosine 3',5'-cyclic monophosphate analogue. These observations are discussed in relation to cell proliferation. The enhanced expression of K+ channels during cell proliferation provides a positive-feedback mechanism resulting in long-term changes in [Ca2+]i required for the G1-S transition in the cell cycle.

scholarly journals Fibroblast Circadian Rhythms of PER2 Expression Depend on Membrane Potential and Intracellular Calcium

2012 ◽  
Vol 29 (6) ◽  
pp. 653-664 ◽  
Author(s):  
Takako Noguchi ◽  
Connie W. Wang ◽  
Haiyun Pan ◽  
David K. Welsh
Keyword(s):  
Membrane Potential ◽  
Circadian Rhythms ◽  
Intracellular Calcium
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