Capacitative Ca2+ entry has been examined in several tissues and, in some, appears to be mediated by nonselective cation channels collectively referred to as "store-operated" cation channels; however, relatively little is known about the electrophysiological properties of these channels in airway smooth muscle. Consequently we examined the electrophysiological characteristics and changes in int...

The vacancy ordering behavior of an A-site deficient perovskite system, Ca1-xLa2x/3TiO3, was studied using atomic resolution scanning transmission electron microscopy (STEM) in conjunction with electron energy-loss spectroscopy (EELS), with the aim of determining the role of A-site composition changes. At low La content (x = 0.2), adopting Pbnm symmetry, there was no indication of long-range or...

The Arabidopsis TCH genes, which encode calmodulin-related proteins and a xyloglucan endotransglycosylase, are shown to be up-regulated in expression following cold shock. We investigated a possible role of fluctuations in intracellular calcium ion concentrations ([CaZ+I) in the cold-shock-induced TCH gene expression. Transgenic plants harboring the apoaequorin gene were generated to monitor [C...

Nanostructured metal fluorides (nanofluorides) are an emerging type of inorganic nanocrystals (NCs) with unique physiochemical properties for advanced applications. One recent demonstration used water-dispersed ultrasmall CaF2 nanofluorides as imaging agents that combined the advantages NCs benefit background-free 19F-magnetic resonance (19F-MRI). Nevertheless, obtaining small a face-centered c...

Lanthanides, also called rare-earth elements, are an interesting group of 15 chemically active, mainly trivalent, f-electronic, silvery-white metals. In fact, lanthanides are not as rare as the name implies, except for promethium, a radioactive artificial element not found in nature. The mean concentrations of lanthanides in the earth's crust are comparable to those of life-important elements l...

The effects of cadmium (Cd2+) on calcium (Ca2+) transport in the gills of rainbow trout (Salmo gairdneri) were studied. The gill epithelium of freshwater fish represents a model for a Ca2+-transporting tight epithelium. Unidirectional Ca2+ fluxes in the gills were estimated in an isolated saline-perfused head preparation. Ca2+ influx was not affected when up to 10 microM Cd were added to the ve...

Stimulus-induced increases in neuronal Ca2+ concentration are important signaling events for transcriptional regulation and neuronal plasticity. Electrical inputs are thought to mediate Ca2+ responses in the soma by triggering action potentials, which in turn open voltage-gated Ca2+ channels in the somatic plasma membrane. It is not yet known to what extent internal Ca2+ amplification contribut...

The effect of anoxia and substrate removal on cytosolic free calcium (Ca2+i), cell calcium, ATP content, and calcium efflux was determined in cultured monkey kidney cells (LLC-MK2) exposed to 95% N2, 5% CO2 for 60 min. In the control period, the basal Ca2+i level was 70.8 +/- 9.4 nM. During 1 h of anoxia without substrate, ATP content decreased 70%, Ca2+i and calcium efflux increased 2.5-fold, ...

Bovine chromaffin-granule ghosts accumulate 45Ca2+ in a temperature- and osmotic-shock-sensitive process; the uptake is saturable, with Km 38 microM and Vmax. 28 nmol/min per mg at 37 degrees C. Entry occurs by exchange with Ca2+ bound to the inner surface of the membrane. It is inhibited non-competitively by Na+, La3+ and Ruthenium Red (Ki 10.7 mM, 7 microM and 2 microM respectively), and comp...

Cai in cultured human sweat gland epithelial monolayers was measured using Fura-2 fluorescence. Thapsigargin (Tg) caused a sustained increase in Cai, the rate of rise being slower but the magnitude greater than with the agonists lysylbradykinin and ATP. Tg caused an irreversible change such that even after it was removed Cai was dependent on the ambient calcium concentration, consistent with th...