Oscillatory electrical activity is regarded as a hallmark of the pancreatic beta cell glucose-dependent excitability pattern. Electrophysiologically recorded membrane potential oscillations in beta cells are associated with in-phase oscillatory cytosolic calcium activity ([Ca(2+)]i) measured with fluorescent probes. Recent high spatial and temporal resolution confocal imaging revealed that gluc...

Contraction in skeletal muscle is initiated when Ca stored in the SR is released into the myoplasm in response to membrane depolarization. Studies of the mechanisms that control SR Ca release are aided by methods that permit estimating the Ca permeability of the SR membrane or, equivalently, the extent of activation of the SR Ca release channels. This quantity is proportional to the rate of Ca ...

While glucose-stimulated insulin secretion depends on Ca(2+) influx through voltage-gated Ca(2+) channels in the cell membrane of the pancreatic β-cell, there is also ample evidence for an important role of intracellular Ca(2+) stores in insulin secretion, particularly in relation to drug stimuli. We report here that thiopental, a common anesthetic agent, triggers insulin secretion from the int...

Beauvois, Melanie C., Charafa Merezak, Jean-Christophe Jonas, Magalie A. Ravier, Jean-Claude Henquin, and Patrick Gilon. Glucose-induced mixed [Ca ]c oscillations in mouse -cells are controlled by the membrane potential and SERCA3 Ca -ATPase of the endoplasmic reticulum. Am J Physiol Cell Physiol 290: C1503–C1511, 2006. First published December 28, 2005; doi:10.1152/ajpcell.00400.2005.—Stimulat...

Large-conductance Ca(2+)-dependent K(+) (BK(Ca)) channels play a critical role in regulating urinary bladder smooth muscle (UBSM) excitability and contractility. Measurements of BK(Ca) currents and intracellular Ca(2+) revealed that BK(Ca) currents are activated by Ca(2+) release events (Ca(2+) sparks) from ryanodine receptors (RyRs) in the sarcoplasmic reticulum. The goals of this project were...

Dendritic cells (DCs) are highly versatile antigen-presenting cells critically involved in both innate and adaptive immunity as well as maintenance of self-tolerance. DC function is governed by Ca(2+) signaling, which directs the DC responses to diverse antigens, including Toll-like receptor ligands, intact bacteria, and microbial toxins. Ca(2+)-sensitive DC functions include DC activation, mat...

Vascular smooth muscle cells exhibit intercellular Ca(2+) waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca(2+) wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca(2+) wave and it was suggested to be the result of the interplay between membrane potential and Ca(2+) dynamic...

Highly selective cellulose acetate (CA)/poly (vinyl alcohol) (PVA)/titanium dioxide (TiO2) imprinted membranes were synthesized by phase inversion and dip coating technique. The CA blend imprinted membrane was synthesized by phase inversion technique with CA as membrane matrix, polyethyleneimine (PEI) as the functional polymer, and the salicylic acid (SA) as the template molecule. The CA/PVA/Ti...

Bianchi, Riccardo, Steven Young, and Robert K. S. Wong. Group I mGluR activation causes voltage-dependent and -independent Ca rises in hippocampal pyramidal cells. J. Neurophysiol. 81: 2903–2913, 1999. Application of the metabotropic glutamate receptor (mGluR) agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) or the selective group I mGluR agonist (S)-3,5-dihydroxyphenylglycine (...

The rate of Ca influx into ghosts containing arsenazo III changes with time, being most rapid during the first 5 min after Ca is added to the outside and declining thereafter. The rate of Ca influx is a nonlinear function of extracellular Ca and plateaus as the latter is increased above 1 mM. The rate of Ca influx was measured as a function of the transmembrane gradients of Na and K and changes...