Voltage-gated Na and Ca2+ channels comprise distinct ion channel superfamilies, yet the carboxy tails of these channels exhibit high homology, hinting at a long-shared and purposeful module. For different Ca2+ channels, carboxyl-tail interactions with calmodulin do elaborate robust and similar forms of Ca2+ regulation. However, Na channels have only shown subtler Ca2+ modulation that differs am...

Thapsigargin stimulates an increase of cytosolic free Ca2+ concentration ([Ca2+],) in, and 45Ca2+ efflux from, a clone of GH4C1 pituitary cells. This increase in [Ca2+] was followed by a lower sustained elevation of [Ca2+]", which required the presence of extracellular Ca2+, and was not inhibited by a Ca2+-channel blocker, nimodipine. Thapsigargin had no effect on inositol phosphate generation....

Ca2+ entry into different diameter cell bodies of dorsal root ganglion (DRG) neurons depolarized with action potential (AP) waveform commands was studied using the whole-cell patch-clamp technique and pharmacological probes. We have previously shown that Ca2+ current expression in DRG neuron cell bodies depends on cell diameter. In small diameter DRG neurons, L- and N-type Ca2+ currents usually...

Beractant, a natural surfactant, induces an antifibrogenic phenotype and apoptosis in normal human lung fibroblasts (NHLF). As intracellular Ca2+ signalling has been related to programmed cell death, we aimed to assess the effect of beractant on intracellular Ca2+ concentration ([Ca2+]i) in NHLF in vitro. Cultured NHLF were loaded with Fura-2 AM (3 μM) and Ca2+ signals were recorded by microflu...

We investigated the effect of various excitatory amino acids on intracellular free Ca2+ concentration ( [Ca2+]i) in single mouse hippocampal neurons in vitro by using the Ca2+-sensitive dye fura-2. In normal physiological solution, glutamate, kainate, N-methyl-D-aspartate, and quisqualate all produced increases in [Ca2+]i. When all extracellular Ca2+ was removed, kainate and N-methyl-D-aspartat...

Ca2+ is implicated as a second messenger in the response of stomata to a range of stimuli. However, the mechanism by which stimulus-induced increases in guard cell cytosolic free Ca2+ ([Ca2+],) are transduced into different physiologiCal responses remains to be explained. Oscillations in [Ca2+], may provide one way in which this can occur. We used photometric and imaging techniques to examine t...

The voltage dependence of the intracellular Ca2+ transients was measured in single rat ventricular myocytes with the fluorescent Ca2+ indicator dye fura-2. The whole-cell voltage clamp technique was used to measure the membrane current, and 0.9 mM fura-2 was loaded into the cell by including it in the dialyzing solution of the patch electrode. A mechanical light chopper operating at 1200 Hz was...

The goal of this study was to examine the relationship between Ca2+ entry through L-type Ca2+ channels and local [Ca2+]i transients (Ca2+ sparks) in single rat cardiac ventricular cells. L-type Ca2+ channels were activated by depolarization of cell-attached membrane patches, and [Ca2+]i was measured simultaneously as fluo 3 fluorescence using laser scanning confocal microscopy. Patch depolariza...

The aim of this study was to investigate the role Ca2+ in process calpain-2 becoming associated myofibrils and potential myofibril-bound calpain degrade myofibrillar proteins. Different concentrations were applied mixed with partially purified calpain-2. induced binding a concentration-dependent manner. half-maximal requirements for proteolysis 0.60 mM 0.29 mM, respectively. To proteolytic acti...

A variety of reagents (local anesthetics, phenothiazines, ruthenium red, ryanodine, dicyclohexylcarbodiimide, R 24571) inhibit Ca2+-induced Ca2+ release from purified canine cardiac sarcoplasmic reticulum (SR). Most of these compounds also increase the rate of net Ca2+ uptake by cardiac SR while moderately inhibiting Ca2+-dependent ATP hydrolysis, and together these two effects produce increase...