Search results for " calcium."
showing 10 items of 341 documents
Glucose-induced alterations of cytosolic free calcium in cultured rat tail artery vascular smooth muscle cells
1995
We have previously suggested that hyperglycemia per se may contribute to diabetic hypertensive and vascular disease by altering cellular ion content. To more directly investigate the potential role of glucose in this process, we measured cytosolic free calcium in primary cultures of vascular smooth muscle cells isolated from Sprague-Dawley rat tail artery before and after incubation with 5 (basal), 10, 15, and 20 mM glucose. Glucose significantly elevated cytosolic free calcium in a dose- and time-dependent manner, from 110.0 +/- 5.4 to 124.5 +/- 9.0, 192.7 +/- 20.4, and 228.4 +/- 21.9 nM at 5, 10, 15, and 20 mM glucose concentrations, respectively. This glucose-induced cytosolic free calci…
More than a pore: How voltage-gated calcium channels act on different levels of neuronal communication regulation.
2021
ABSTRACT Voltage-gated calcium channels (VGCCs) represent key regulators of the calcium influx through the plasma membrane of excitable cells, like neurons. Activated by the depolarization of the membrane, the opening of VGCCs induces very transient and local changes in the intracellular calcium concentration, known as calcium nanodomains, that in turn trigger calcium-dependent signaling cascades and the release of chemical neurotransmitters. Based on their central importance as concierges of excitation-secretion coupling and therefore neuronal communication, VGCCs have been studied in multiple aspects of neuronal function and malfunction. However, studies on molecular interaction partners …
Aggregation and Gel Formation in Basic Silico−Calco−Alkaline Solutions Studied: A SAXS, SANS, and ELS Study
1999
Gelation of strongly basic silico−alkaline solutions was promoted by appropriate additions of calcium ions. The structure of the aggregates formed in the precursor sols and the resulting gels were studied, within a wide length scale, using small-angle X-ray, small-angle neutron, and elastic light scattering. The study of the kinetics of aggregation was performed in situ. The experimental results demonstrate that gels are composed of aggregates exhibiting a fractal structure, large particles formed in the solutions just after calcium addition and, in some cases, small primary particles remaining in the solution phase. The structural features of the gels are strongly dependent on the concentr…
Discoordinate regulation of different K channels in cultured rat skeletal muscle by nerve growth factor
1999
We investigated the effects of nerve growth factor (NGF) on expression of K+ channels in cultured skeletal muscle. The channels studied were (1) charybdotoxin (ChTx)-sensitive channels by using a polyclonal antibody raised in rabbits against ChTx, (2) Kv1.5 voltage-sensitive channels, and (3) apamin-sensitive (afterhyperpolarization) channels. Crude homogenates were prepared from cultures made from limb muscles of 1-2-day-old rat pups for identification of ChTx-sensitive and Kv1.5 channels by Western blotting techniques. Apamin-sensitive K+ channels were studied by measurement of specific [125I]-apamin binding by whole cell preparations. ChTx-sensitive channels display a fusion-related incr…
Calcium in the prevention of postmenopausal osteoporosis: EMAS clinical guide
2017
Abstract Introduction Postmenopausal osteoporosis is a highly prevalent disease. Prevention through lifestyle measures includes an adequate calcium intake. Despite the guidance provided by scientific societies and governmental bodies worldwide, many issues remain unresolved. Aims To provide evidence regarding the impact of calcium intake on the prevention of postmenopausal osteoporosis and critically appraise current guidelines. Materials and methods Literature review and consensus of expert opinion. Results and conclusion The recommended daily intake of calcium varies between 700 and 1200 mg of elemental calcium, depending on the endorsing source. Although calcium can be derived either fro…
Ikaros-1 couples cell cycle arrest of late striatal precursors with neurogenesis of enkephalinergic neurons
2010
et al.
Mitochondrial cannabinoid receptors gate corticosterone impact on novel object recognition
2023
: Corticosteroid-mediated stress responses require the activation of complex brain circuits involving mitochondrial activity, but the underlying cellular and molecular mechanisms are scantly known. The endocannabinoid system is implicated in stress coping, and it can directly regulate brain mitochondrial functions via type 1 cannabinoid (CB1) receptors associated with mitochondrial membranes (mtCB1). In this study, we show that the impairing effect of corticosterone in the novel object recognition (NOR) task in mice requires mtCB1 receptors and the regulation of mitochondrial calcium levels in neurons. Different brain circuits are modulated by this mechanism to mediate the impact of cortico…
Ab Initio Structure Determination of Vaterite by Automated Electron Diffraction
2012
tion that is fundamental for understanding material properties. Still, a number of compounds have eluded such kinds of analysis because they are nanocrystalline, highly disordered, with strong pseudosymmetries or available only in small amounts in polyphasic or polymorphic systems. These materials are crystallographically intractable with conventional Xray or synchrotron radiation diffraction techniques. Single nanoparticles can be visualized by high-resolution transmission electron microscopy (HR-TEM) up to sub�ngstrom resolution, [2] but obtaining 3D information is still a difficult task, especially for highly beam-sensitive materials and crystal structures with long cell parameters. Elec…
Trapping Amorphous Intermediates of Carbonates – A Combined Total Scattering and NMR Study
2018
Crystallization via metastable phases plays an important role in chemical manufacturing, biomineralization, and protein crystallization, but the kinetic pathways leading from metastable phases to the stable crystalline modifications are not well understood. In particular, the fast crystallization of amorphous intermediates makes a detailed characterization challenging. To circumvent this problem, we devised a system that allows trapping and stabilizing the amorphous intermediates of representative carbonates (calcium, strontium, barium, manganese, and cadmium). The long-term stabilization of these transient species enabled a detailed investigation of their composition, structure, and morpho…
Changes in cytosolic calcium in response to noxious heat and their relationship to vanilloid receptors in rat dorsal root ganglion neurons.
2001
Heat transduction mechanisms in primary nociceptive afferents have been suggested to involve a vanilloid receptor channel with high calcium permeability. To characterize the changes in free cytosolic calcium evoked by noxious heat stimuli (< or =51 degrees C, 10s), we performed microfluorometric measurements in acutely dissociated small dorsal root ganglion neurons (< or =32.5 microm) of adult rats using the dye FURA-2. Only neurons that responded with a reversible increase in intracellular calcium to high potassium were evaluated. Heat-induced calcium transients (exceeding mean + 3S.D. of the temperature dependence of the dye) were found in 66 of 105 neurons. These transients increased non…