BioAssay record AID 225394 submitted by ChEMBL: Percent increase in intracellular calcium ion concentration ([Ca2+]i) using CHO cells, stably transfected with human muscarinic m3 acetylcholine receptor (AChR); nd=Not determined.
Purpose.: Previously, retinopetal axons containing histamine and dopaminergic neurons expressing histamine H1-receptor had been localized in mouse retinas using anatomic techniques. The goal of these experiments was to demonstrate that these receptors are functional. Methods.: Dopaminergic cells were acutely isolated from retinas of transgenic mice expressing red fluorescent protein under control of the tyrosine hydroxylase promoter and loaded with the calcium indicator Fura-2. Results.: Under control conditions, there were spontaneous oscillations in the levels of free intracellular calcium in dopaminergic cells. These oscillations were abolished in nominally calcium-free extracellular medium and in 1 μM tetrodotoxin, findings suggesting that the oscillations were mediated by calcium entry across the plasma membrane in response to sodium-dependent action potentials. Histamine increased the mean free intracellular calcium in the dopaminergic cells by increasing the frequency and/or amplitude of ...
TY - JOUR. T1 - Transmembrane Ca2+ gradient-mediated change of fluidity in the inner layer of phospholipids modulates Ca2+-ATPase of sarcoplasmic reticulum. AU - Tu, Yaping. AU - Xu, H.. AU - Yang, F. Y.. PY - 1994. Y1 - 1994. N2 - Sarcoplasmic reticulum (SR) vesicles with (1000 folds) or without transmembrane Ca2+ gradient have been prepared. Different fluorescence probes (DPH, TMA-DPH and n-AS), were used to determine the effect of transmembrane Ca2+ gradient on the lipid fluidity both in outer and inner layer of Ca2+-ATPase-containing SR vesicles. The results showed that transmembrane Ca2+ gradient could significantly decrease the fluidity of the inner layer of SR membrane, while no obvious change was monitored in the outer layer. This may be deduced that Ca2+-ATPase might be modulated mainly by the transmembrane Ca2+ gradient-mediated alteration of physical state of phospholipid in the inner layer of SR membrane.. AB - Sarcoplasmic reticulum (SR) vesicles with (1000 folds) or without ...
In endothelial cells, a bolus of hydrogen peroxide (H2O2) or oxygen metabolites generated by hypoxanthine-xanthine oxidase (HX-XO) increased the mitochondrial calcium concentration [Ca2+]m. Both agents caused a biphasic increase in [Ca2+]m which was preceded by a rise in cytosolic free calcium concentration [Ca2+]c (18 and 6 seconds for H2O2 and HX-XO, respectively). The peak and plateau elevations of [Ca2+] were consistently higher in the mitochondrial matrix than in the cytosol. In Ca2+-free/EGTA medium, the plateau phase of elevated [Ca2+] evoked by H2O2 due to capacitative Ca2+ influx was abolished in the cytosol, but was maintained in the mitochondria. In contrast to H2O2 and HX-XO, ATP which binds the P2Y purinoceptors induced an increase in [Ca2+]m that was similar to that of [Ca2+]c. When cells were first stimulated with inositol 1,4, 5-trisphosphate-generating agonists or the Ca2+-ATPase inhibitor cyclopiazonic acid (CPA), subsequent addition of H2O2 did not affect [Ca2+]c, but still ...
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Among different pathways coordinating intracellular signaling, the most prominent is intracellular calcium signaling (ICS), controlling various cellular processes including proliferation, motility, apoptosis and differentiation [1]. ICS is impressively diverse and consists of mechanisms that differ in frequency, amplitude and spatio-temporal patterning depending on an extensive molecular repertoire of signaling components. The free intracellular calcium concentration ([Ca2+i) of a resting cell is in the range of 10-100 nM. Following physiological stimulation, [Ca2+i levels can rise up to 1-2 μM concentrations. ICS is codified by the peak amplitude and frequency of [Ca2+i transients, promoted by the entry of external Ca2+ through Ca2+ channels or the release of Ca2+ from internal stores. These internal stores are deposited within internal membrane structures such as the endoplasmic reticulum (ER). Following activation of G-protein-coupled receptors, phospholipase C-β (PLC-β) cleaves ...
To examine the role of Ca2+ in early neuronal death, we studied the impact of free intracellular calcium concentration ([Ca2+]i) on survivability in populations of cultured mouse spinal neurons. We asked whether early neurotoxicity was triggered by Ca2+ influx, whether elevated [Ca2+]i was a predictive indicator of impending neuronal death, and whether factors other than [Ca2+]i increases influenced Ca2+ neurotoxicity. We found that when neurons were lethally challenged with excitatory amino acids or high K+, they experienced a biphasic [Ca2+]i increase characterized by a primary [Ca2+]i transient that decayed within minutes, followed by a secondary, sustained, and irreversible [Ca2+]i rise that indicated imminent cell death. We showed that in the case of glutamate-triggered neurotoxicity, processes triggering eventual cell death required Ca2+ influx, and that neurotoxicity was a function of the transmembrane Ca2+ gradient. Fura-2 Ca2+ imaging revealed a "ceiling" on measurable changes in ...
The sarcoplasmic reticulum (SR) is the major intracellular calcium storage depot in cardiac muscle. Cycling of calcium between the lumen of the SR and the myoplasmic space occurs repetitively during each heart beat. Excitation-contraction coupling in the heart begins when calcium entry through voltage-gated L-type calcium channels in the sarcolemma induces the opening of calcium release channels (also known as ryanodine receptors, or RyR) in the adjacent SR. The majority of the calcium that enters the cytosol during the early portion of each cycle is then resequestered into the SR lumen via the actions of the calcium uptake protein, (sarco)endoplasmic reticulum calcium adenosine triphosphatase (SERCA). Tight regulation of the timing and quantity of these intracellular calcium fluxes is critical to achieve graded contractility and relaxation of the heart muscle. Such control allows optimal matching of cardiac function to heart rate and metabolic needs of the body. The mechanisms of ...
The cytoplasmic free calcium concentration ([Ca2+]i) was studied in Fura-2/AM loaded granule neurones in acutely prepared cerebellar slices isolated from neonatal (6 days old) and adult (30 days old) mice. Bath application of elevated (10-50 mM) KCl-containing extracellular solutions evoked [Ca2+]i rise which was dependent on extracellular Ca2+. The K(+)-induced [Ca2+]i elevation was inhibited to different extends by verapamil, nickel and omega-conotoxin suggesting the coexpression of different subtypes of plasmalemmal voltage-gated Ca2+ channels. Bath application of caffeine (10-40 mM) elevated [Ca2+]i by release of Ca2+ from intracellular stores. Caffeine-induced [Ca2+]i elevation was inhibited by 100 microM ryanodine and 500 nM thapsigargin. Depletion of internal Ca2+ stores by caffeine, or blockade of Ca2+ release channels by ryanodine, did not affect depolarization-induced [Ca2+]i transients, suggesting negligible involvement of Ca(2+)-induced Ca2+ release in [Ca2+]i signal generation following
BioAssay record AID 270304 submitted by ChEMBL: Activity at human recombinant iGluR2 flip expressed in HEK293 cells measured as change in intracellular calcium ion concentration in presence of glutamate by FLIPR assay.
Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Here, we...
Loss of the mitochondrial membrane potential results in a significant inhibition of calcium influx through calcium release-activated channels (CRAC) in Jurkat cells suspended in the medium of pH lower than 7.4. This effect disappears when the medium pH increases. Alkalinisation of the cytosol achieved by the addition of NH(4)Cl to the cells pretreated with thapsigargin, CCCP and CaCl(2), suspended in the medium of pH 7.2, does not affect CRAC activity, while alkalisation of the extracellular milieu by NaOH results in a strong stimulation of calcium entry. Thus, the mitochondrial effect on CRAC is exclusively related to the extracellular pH. Coupled mitochondria are able to take up Ca(2+) accumulated in the close proximity of CRAC. This protects these channels against feedback inhibition exerted by high [Ca(2+)](c). We conclude that CRAC may exist in two conformations: inhibitable and not inhibitable by cytosolic Ca(2+). Lower extracellular pH promotes the former one. This explains a much higher
Calcium plays an important role in several body functions, including muscle contractions, enzyme function, and nerve conduction. Calcium is stored in the bones.. Disorders affecting calcium metabolism require clinical care by a physician or other health care professional. Listed in the directory below are some of the disorders that affect calcium metabolism, for which we have provided a brief overview.. If you cannot find the information in which you are interested, please visit the Diabetes & Other Endocrine and Metabolic Disorders Online Resources page in this website for an Internet address that may contain additional information on that topic.. ...
Proper functioning of organelles such as the ER or the Golgi apparatus requires luminal accumulation of Ca2+ at high concentrations. Here we describe a ratiometric low-affinity Ca2+ sensor of the GFP-aequorin protein (GAP) family optimized for measurements in high-Ca2+ concentration environments. Transgenic animals expressing the ER-targeted sensor allowed monitoring of Ca2+ signals inside the organelle. The use of the sensor was demonstrated under three experimental paradigms: (1) ER Ca2+ oscillations in cultured astrocytes, (2) ex vivo functional mapping of cholinergic receptors triggering ER Ca2+ release in acute hippocampal slices from transgenic mice, and (3) in vivo sarcoplasmic reticulum Ca2+ dynamics in the muscle of transgenic flies. Our results provide proof of the suitability of the new biosensors to monitor Ca2+ dynamics inside intracellular organelles under physiological conditions and open an avenue to explore complex Ca2+ signaling in animal models of health and disease ...
PTH, together with vitamin D and calcitonin, brings about mobilization of calcium and phosphate from the skeletal system and increases the uptake of calcium in the intestine and the excretion of phosphate via the kidneys. The constancy of the blood calcium level is ensured by the interaction of PTH and calcitonin. The secretion of PTH is inhibited by high calcium concentrations and promoted by low calcium concentrations ...
A patient has a total serum calcium level of 13.3 mg/dL (3.3 mmol/L). The nurse will anticipate the need to teach the patient about testing for
A patient has a total serum calcium level of 13.3 mg/dL (3.3 mmol/L). The nurse will anticipate the need to teach the patient about testing for
Sugar solutions taste sweeter when warm. Talavera et al. now provide a molecular mechanism for this phenomenon. They identified the transient receptor potential (TRP) family members TRPM5 and TRPM4 as thermally activated, calcium-dependent cation channels. TRPM5 and the related protein TRP4 are calcium-impermeable cation channels. When expressed in human embryonic kidney (HEK) 293 cells, these proteins exhibited a shift in voltage dependence in response to increased temperature in the range of 15°C to 35°C, such that at higher temperatures the channels were more active. Activation of the channels by heat required the presence of intracellular calcium, despite the fact that these channels do not conduct calcium ions. Therefore, they are poised to serve as coincidence detectors, sensing a stimulus that increases intracellular calcium concentrations, such as the presence of a taste ligand that activates a taste receptor, as well as temperature. Indeed, knockout mice lacking TRPM5 did not show any ...
Important element in road towards development of new drugs for neurodegenerative diseases All living cells keep their cellular calcium concentration at a very low level. Since a small increase in calcium can affect many critical cellular functions (an elevated calcium concentration over an extended period can induce cell death), powerful cellular mechanisms ensure that calcium concentration quickly returns to its low level.. It is known that impairments of cellular calcium regulation underlie almost all neurodegenerative diseases. For example, age-related loss of calcium regulation was shown to promote cell vulnerability in Alzheimers disease.. In a study recently published in the Journal of Neuroscience, Hebrew University of Jerusalem researchers, along with others from Israel and the US, presented their findings of a previously undescribed cellular mechanism which is essential for keeping cellular calcium concentration low. This mechanism operates together with other already characterized ...
Gomez-Ospina et al. provide evidence for an intriguing mechanism whereby voltage-dependent calcium channels modulate gene transcription. Calcium entry through voltage-gated channels in the plasma membrane provides a link between electrical activity and changes in gene expression. Gomez-Ospina et al. found that, whereas an antibody that recognized the full-length Cav1.2 calcium channel localized to membrane and cytosolic fractions of rat brain cortex, an antibody that recognized the C-terminal fragment, which is proteolytically cleaved, appeared in the nucleus. The C-terminal fragment was abundant in nuclei of GABAergic neurons; moreover, nuclear fluorescence was apparent in neurons or glioblastoma cells expressing a construct in which the Cav1.2 C terminus was fluorescently labeled. Treatments aimed at lowering cytoplasmic calcium increased nuclear abundance of the Cav1.2 fragment, whereas treatments that increase intracellular calcium decreased it. The Cav1.2 fragment immunoprecipitated with ...
We found a doubling of risk for fatal prostate cancer among men in the highest tertile of total serum calcium and a tripling of risk for men in the highest tertile of ionized serum calcium. The results for total serum calcium are consistent with our previous findings for prostate cancer mortality in NHANES I in which we observed a multivariable-adjusted RR of 2.68 (5). This is the first study to examine prostate cancer risk in relation to prediagnostic levels of ionized serum calcium.. Each individual is believed to have his or her own set point for serum calcium that is under genetic control (9). The concentration of ionized serum calcium in a given individual normally does not deviate by ,2% from its set point (10). Conversely, there is considerable variation in calcium levels between individuals, with normal levels of total serum calcium ranging from 8.5 to 10.5 mg/dL (2.1-2.6 mmol/L; ref. 11).. This study has several strengths. It is hypothesis testing, is prospective, and uses a population ...
Fig.: Fibre-optic recording of YC3.60 signals in barrel cortex. Schematics of a setup (left) and functional signals in a freely-moving mouse (right).. Image: Mazahir T. Hasan. Neurons communicate with one another via so-called action potentials. During an action potential, voltage-gated calcium channels are opened resulting in rapid calcium ion influx. Because of this tight coupling, fluorescent calcium indicator proteins can visualize action potentials. These proteins have two fluorescent subunits, one of which radiates yellow light and the other blue. When the proteins bind calcium, the proportion of yellow to blue light changes. Colour variation from blue light towards yellow thus reports different calcium levels - which is why the protein has been dubbed a "cameleon".. Measuring action potentials optically. With the cameleon protein YC3.60, a fairly new variant, the scientists succeeded in recording the reaction of nerve cells to sensory stimuli in the intact brain of mice: every time the ...
In addition to transmitting involving extracellular free of charge contaminants, a generally accepted super model tiffany livingston of pathogen distribution is one wherein pathogen replicates in one cell, producing infectious contaminants that transmit to the following cell via cell junctions or induced polarized connections. outside the group had been bad for pathogen immediate-early phrase generally. We further display, using separated monolayer assays spatially, that at least one element of this activated migration is certainly the paracrine pleasure of a cytotactic response from contaminated cells to uninfected cells. The lifetime of this procedure adjustments our concept of pathogen transmitting and the potential features, pathogen, and web host elements included. Launch The systems included in the transmitting of contagious infections between cells are of fundamental importance for our general understanding of computer virus duplication, virulence, and pathogenesis and for long lasting ...
TY - JOUR. T1 - CXCL10-induced cell death in neurons. T2 - Role of calcium dysregulation. AU - Sui, Yongjun. AU - Stehno-Bittel, Lisa. AU - Li, Shanping. AU - Loganathan, Rajprasad. AU - Dhillon, Navneet K.. AU - Pinson, David. AU - Nath, Avindra. AU - Kolson, Dennis. AU - Narayan, Opendra. AU - Buch, Shilpa. PY - 2006/2. Y1 - 2006/2. N2 - Chemokines play a key role in the regulation of central nervous system disease. CXCL10 over-expression has been observed in several neurodegenerative diseases, including multiple sclerosis, Alzheimers disease and HIV-associated dementia. More recent studies by others and us have shown that CXCL10 elicits apoptosis in fetal neurons. The mechanism of CXCL10-mediated neurotoxicity, however, remains unclear. In this study, we provide evidence for the direct role of Ca2+ dysregulation in CXCL10-mediated apoptosis. We demonstrate that treatment of fetal neuronal cultures with exogenous CXCL10 produced elevations in intracellular Ca2+ and that this effect was ...
Under appropriate conditions macrophage cytosolic extracts can form a three-dimensional gel network of cross-linked actin filaments. These cytoplasmic gels are mainly composed of actin, filamin, alpha-actinin, and two new proteins of about 70,000 and 55,000 Mr (70 and 55 K). The behaviour of 70 K protein was found to be remarkably affected by Ca2+. Ca2+ treatment of isolated cytoplasmic gels led to the selective solubilization of the 70 K protein along with a 17 K polypeptide. Half-maximal recovery in the supernatant fraction was obtained from about 0.15 microM free Ca2+. The cytoplasmic gel constituents solubilized in high ionic strength buffer were able to re-assemble into an insoluble actin network when returned to near physiological ionic conditions. However, the inclusion of micromolar Ca2+ prevented the re-association of 70 K protein with actin in these complexes. As compared to the 70 K protein, alpha-actinin was fully resistant to any variations in Ca2+ concentrations. On the other hand, ...
By: Andy De Santis, RD and Dr. Kathleen Regan, ND. Andy De Santis is a Registered Dietician practicing at Innate Wellness High Park. He focuses on creating diet plans for patients of Innate Wellness. If you are interested in having a customized nutrition program created for you, please call the High Park Clinic. Calcium is one of the most abundant minerals found in the human body. Most calcium is stored either in our bones or our teeth, leaving a small amount found in other tissues or circulating through our blood. The way our bodies use and absorb calcium depends on the presence of specific nutrients, such as Vitamin D, and specific hormones, such as parathyroid hormone and calcitonin. Calcium levels are also influenced by specific female hormones such as estrogen (which increases calcium absorption).. Declining levels of estrogen as women age, through menopause, after hysterectomy, or via estrogen reducing drugs such as Tamoxifen (post-breast cancer treatment) can dramatically affect calcium ...
The present study reports a potentiating effect of glibenclamide on quantal catecholamine secretion evoked from individual PC-12 cells by exposure to solutions containing either 50 mmK+ or 30 mm caffeine. Using either stimulus, this secretion is Ca2+-dependent. For K+-evoked release, Ca2+ influx through voltage-gated Ca2+ channels is a prerequisite for exocytosis, and of the different channel types present in PC-12 cells (Liu et al., 1996), the N-type appear to be most closely coupled to depolarization-mediated release because ω-conotoxin GVIA causes profound inhibition of such release (Taylor and Peers, 1998). Caffeine has recently been demonstrated to evoke secretion from PC-12 cells (Koizume and Inoue, 1998), and the present study indicates that this release is quantal (i.e., because of exocytosis) (Fig. 6). Caffeine causes release of Ca2+ from intracellular stores (presumably via activation of ryanodine receptors), and this store depletion in turn activates CCE. Koizume and Inoue (1998) ...
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Cells have developed a variety of mechanisms to keep free calcium ion concentrations at very low levels in the cytosol. These mechanisms allow transient increases in cell calcium concentrations to be used as signals to trigger a variety of cellular processes, gene expression being one of them. Skeletal muscle relies on nerve activity both for contraction and also for the expression of genes related to pathways that include survival and the plastic changes required for adaptation to exercise. A particular pathway that involves Cav1.1 as a voltage sensor for nerve activity, pannexin-1 channels to release ATP to the extracellular milieu, purinergic P2Y receptors to link the signal ...
Video articles in JoVE about inositol 1 4 5 trisphosphate include Imaging Local Ca2+ Signals in Cultured Mammalian Cells, Direct Imaging of ER Calcium with Targeted-Esterase Induced Dye Loading (TED), Monitoring ER/SR Calcium Release with the Targeted Ca2+ Sensor CatchER+, PIP-on-a-chip: A Label-free Study of Protein-phosphoinositide Interactions, Radiolabeling and Quantification of Cellular Levels of Phosphoinositides by High Performance Liquid Chromatography-coupled Flow Scintillation, Preparation of Quality Inositol Pyrophosphates, Characterization of G Protein-coupled Receptors by a Fluorescence-based Calcium Mobilization Assay, Cytosolic Calcium Measurements in Renal Epithelial Cells by Flow Cytometry, Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins, A Cell Culture Model of Resistance Arteries , Preparation of Pancreatic Acinar Cells for the Purpose of Calcium Imaging, Cell Injury Measurements, and Adenoviral Infection, Lignin Down
When the estrogen produced by the body is reduced, the bones inadequately absorb and utilize calcium. This resulting drop in calcium levels can lead to decreased bone mass and osteoporosis later in...
Natural Vitality Natural Calm Plus Calcium balances a highly soluble and bioavailable form of calcium with Natural Calm the best-selling, award-winning ionic magnesium that mixes easily in water to restore healthy magnesium levels quickly and effectively.
In the present study we showed increased TRPV1 activity after prestimulation of TRPA1, both in HEK cells and DRG neurons. This was dependent on calcium, AC, and PKA. Mutation of the putative phosphorylation site serine 116 in TRPV1 also abolished increased TRPV1 activity after TRPA1 stimulation. Together, our findings suggest that TRPA1 activation causes an influx of calcium and increases calcium-sensitive AC activity, cAMP accumulation, and subsequent PKA activation. This results in phosphorylation and sensitization of TRPV1.. Although some studies showed direct activation of TRPV1 by MO at high concentrations (Ohta et al., 2007; Everaerts et al., 2011; Gees et al., 2013), our control experiments and other studies showed that MO at a concentration of 20 µM did not directly activate TRPV1 (Fig. 2D; Jordt et al., 2004; Everaerts et al., 2011).. Approximately 30% to 50% of TRPV1-expressing small- to medium-sized peripheral sensory neurons coexpress TRPA1, and almost all TRPA1-positive neurons ...
Regehrs laboratory studies the implication of calcium Ca2+ as it affects synaptic strength. Neurons communicate with one another via synapses. Regehr was one of the first to use fluorescent imaging to see the synaptic activity occurring in the brain. A dye alters the fluorenscence properties when attached to calcium, and changes in intracellular calcium are associated with neuronal activity (firing of action potentials). Using fluorescence-microscopy techniques, calcium levels are detected, and therefore the influx of calcium in the presynaptic neuron ...
MAIL VIA INTERNET FROM BIOSCI-REQUEST at genbank.bio.net THURSDAY 09/10/92 6:15:03 A.M. , , Received: from CU.NIH.GOV by NIHCU (Mailer) id 9613; , Thu, 10 Sep 92 06:15:03 EDT , Received: from GENBANK.BIO.NET by CU.NIH.GOV , with TCP; Thu, 10 Sep 92 6:15:00 EDT , Received: by genbank.bio.net (5.65/IG-2.0) , id AA05730; Thu, 10 Sep 92 03:15:24 -0700 , Received: by genbank.bio.net (5.65/IG-2.0) , id AA05723; Thu, 10 Sep 92 03:15:22 -0700 , Message-Id: ,9209101015.AA05723 at genbank.bio.net, , To: bio-soft at genbank.bio.net , From: Fergus_Doherty at vme.ccc.nottingham.ac.uk , Subject: Calculating free Ca2++ with EGTA buffers , Date: 10 Sep 92 10:00:35 GMT , Sender: list-admin at daresbury.ac.uk , Original-To: BIO-SOFT at uk.ac.daresbury , , Can anyone help me to calculate free Ca2++ in EGTA/CA buffers? Basically , I want to determine the effect of Ca on enzyme activity, and relatedly , translocation of an enzyme to membranes-which is Ca -dependent. I need , to include EGTA to completely inhibit the ...
Repolarization alternans has been considered a strong marker of electrical instability. The objective of this study was to investigate the hypothesis that ischemia-induced contrasting effects on the kinetics of membrane voltage and intracellular calcium transient (Ca(i)T) can explain the vulnerability of the ischemic heart to repolarization alternans. Ischemia-induced changes in action potential (AP) and Ca(i)T resulting in alternans were investigated in perfused Langendorff guinea pig hearts subjected to 10-15 min of global no-flow ischemia followed by 10-15 min of reperfusion. The heart was stained with 100 microl of rhod-2 AM and 25 microl of RH-237, and AP and Ca(i)T were simultaneously recorded with an optical mapping system of two 16 x 16 photodiode arrays. Ischemia was associated with shortening of AP duration (D) but delayed upstroke, broadening of peak, and slowed decay of Ca(i)T resulting in a significant increase of Ca(i)T-D. The changes in APD were spatially heterogeneous in contrast to a
Phospholipase C (PLC) regulates various cellular processes by catalyzing the formation of inositol-1,4,5-trisphosphate (IP3) and diacylglycerol from phosphatidylinositol-4,5-bisphosphate (PIP2). Here, we have investigated the influence of Ca2+ on receptor-triggered PLC activity in individual insulin-secreting β-cells. Evanescent wave microscopy was used to record PLC activity using green fluorescent protein (GFP)-tagged PIP2/IP3-binding pleckstrin homology domain from PLCδ1, and the cytoplasmic Ca2+ concentration ([Ca2+]i) was simultaneously measured using the indicator Fura Red. Stimulation of MIN6 β-cells with the muscarinic-receptor agonist carbachol induced rapid and sustained PLC activation. By contrast, only transient activation was observed after stimulation in the absence of extracellular Ca2+ or in the presence of the non-selective Ca2+ channel inhibitor La3+. The Ca2+-dependent sustained phase of PLC activity did not require voltage-gated Ca2+ influx, as hyperpolarization with ...
A: 1. by increasing open time of the calcium channels, and more calcium rush into the cardiac muscle cell. From the extracellular fluid. 2. Phosphorylate (activate) phospholamban, whch increases Calcium ATPase in the sarcoplasmic reticulum. This increases calcium stores in the SR, so more is released when needed, leading to forceful contractions. Calcium is also removed from the cytosol faster, shortening the calcium-troponin binding time, which causes shorter duration of contraction.. Q: What is the isovolumic systole ...
In this study, we provide in vivo evidence that SEL-12, a C. elegans PSEN homolog, is involved in regulating calcium homeostasis and impacts mitochondrial morphology and function. In addition, we have found that the calcium dysregulation observed in SEL-12-deficient animals arises from ER stores and that this defect leads to increased mitochondrial uptake of calcium, which drives the mitochondrial defects observed in sel-12 mutants. Furthermore, we show that the role of SEL-12 in regulating mitochondrial function is independent of its role in γ-secretase function and that the mitochondrial defects observed in sel-12 mutants are caused in part by the opening of the mPTP and elevated DRP-1-dependent mitochondrial fission.. Although the role of PSEN in AD progression remains unclear (Sherrington et al. 1995), similar to our findings, calcium dysregulation has been observed in various models of mutant PSEN function as well as tissue samples from AD patients (Ito et al. 1994; Leissring et al. 1999; ...
EMG - Force Relationship An EMG signal will not necessarily reflect the total amount of force (or torque) a muscle can generate The number of motor units recorded by electrodes will be less than the total number of motor units that are firing - electrodes cant pick-up all motor units
Biphasic contractions were produced in dog trabeculae by replacing 90-95% of the calcium in the bathing solution with strontium. These conditions produced prolonged action potentials accompanied by contractions with two distinct phasic components. The early component disappeared slowly when the remaining Ca++ was removed, whereas the late component was eliminated quickly when Sr++ was removed. Manganese ion (0.25 mM) preferentially decreased the late component without changing the action potential, whereas caffeine and ryanodine decreased or eliminated the early component. Ryanodine did not alter the action potential. Isoproterenol rapidly increased the early component and, more slowly and to a lesser degree, increased the late component. The results suggest that the early component is caused by intracellular release of activator cation, probably from the sarcoplasmic reticulum, whereas the late component is the result of Sr++ entry across the sarcolemma, possibly by way of the slow inward ...
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Blood collections analyzed for measurements of PTH(1-34), PTH(1-84), 25-OH vitamin D, 1,25(OH)2 vitamin D, markers of bone metabolism, and fractional excretion of calcium measurements ...
Laboratory technical support services. 1. Vascular endothelial tube formation:an in vitro matrigel angiogenesis assay.. 2. Agiogenesis in vivo within a Matrigel plug in mice. 3. Endothelial cell (human and mouse) transfection with siRNA and cDNA. 4. Endothelial cell expressing GFP (high efficient electroporation transfection). 5. Endothelial Cell transendothelial electrical resistance (TER). 6. Cell treatment. 7. Imaging. 8. PCR/RT-PCR. 9. ELISA. 10. FACS. 11. Immunoprecipitiation. 12. Immunoblotting. 13. Calcium measurement assay. 14. ROS measurement assay. 15. Animal in vivo studies, including perfused mouse lung preparation (liquid and protein permeability). And More….. ...
This thesis documents the exploration of tools and techniques which were used to determine the existence of patterns within and relationships between the voltage and calcium measurements from individual bacterial cells. The research lies in the broad domain of bacterial electro-physiology.
Increasing evidence supports the idea that calcium levels are altered in plant cells in response to abiotic stress. The stress-induced perturbation in cytosolic calcium ion (Ca2+) levels is sensed by calcium-binding proteins (Ca2+ sensors). In plants, the Ca2+-dependent protein kinase (CPKs or CDPKs) family represents a unique group of calcium sensors. Within a single polypeptide, CPKs contain a catalytic Ser/Thr kinase domain fused to a calmodulin domain. This unique structure allows the CPKs to recognize specific calcium signatures and transduce the signal into phosphorylation cascades. CPKs have been identified throughout the plant kingdom and in some protozoans, but not in animals. The available information on plant CPKs indicates that CPKs are encoded by multigene families consisting of 31 genes in rice (Oryza sativa) and 34 genes in Arabidopsis. Although some of the CPK genes are ubiquitously expressed, others show a tissue-specific pattern of expression or are regulated by stress ...
3.4g of powder in 8oz liquid, or 2 wafers or 5 caps with 8oz liquid 1-3 times daily, or 5 caps plus calcium with 8oz liquid up to 4 times daily. Drink 8 more ounces of liquid after powder. Results in 12-72 hours.. ...
Liquids that have a pH of 7 are neutral. Those with lower numbers are considered acidic and those with a pH over 7 are alkaline.. Your bodys preferred pH is 7.4, and survival does not allow much leeway. The full pH scale for all liquids runs from zero to 14. For people, a pH of less than 7.35 or more than 7.45 can lead to health problems. This is a swing of less than 1% of the full pH range. In other words, you cannot be in optimal health in 99% of the possible pH range found in nature.. A pH of less than 6.8 or more than 7.8 is deadly. This is a variation of 7% of the full pH range. In other words, you cant even survive in 93% of the possible pH range found in nature.. Your lungs and kidneys are the primary defenses to keep your pH in the optimal zone, with bones and intestines also important. However, your bodys ability to buffer a pH that is too high or too low can be overwhelmed. Symptoms of being too alkaline include heart dysrhythmias, lightheadedness, confusion, irritability, headache, ...
Researchers studying the remarkable health of the islanders have found that their diets are far superior to that of most Americans (see The Okinawa Program, Clarkson Potter, 2001). Traditional Okinawans consume at least seven servings of vegetables and fruits daily, an equal number of grains, two daily servings of soy products, green tea every day and fish rich in omega-3s (several times a week) Meat, poultry and eggs account for only three percent of the Okinawan diet.. Elderly Okinawans are more physically active than elderly Americans and also enjoy strong social networks and community support. I believe their good health has much more to do with diet, with their physically active lifestyle, and with community support than with their drinking water.. Furthermore, the notion that you can enhance health by making the body more alkaline has no scientific basis. Nor is there evidence that drinking alkaline water does anyone any good. Alkaline or "hard" water (due to high calcium concentrations) ...
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Retinal waves are bursts of activity occurring spontaneously in the developing retina of vertebrate species, contributing to the shaping of the visual system organization and disappear short after birth. Waves during development are a transient process which evolves dynamically exhibiting different features. Based on our previous modelling work [1,2], we now propose a classification of stage II retinal waves patterns as a function of acetylcholine coupling strength and a possible mechanism for waves generation. Our model predicts that spatiotemporal patterns evolve upon maturation or pharmacological manipulation and that waves emerge from a complete homogeneous state without the need of the variability of a neural population. Context & Motivation SACs dynamically change their synaptic coupling upon maturation Coupled cholinergic SACs [3] Cholinergic current evolution upon maturation [4]-70 mV 60mV 0 0.8 88 nM 300 nM 0.2 0.4 0.4 0.2 Bursting sAHP Increase of Calcium load during bursting Calcium controls
These different types of calcium are used for their own special properties. The use of these calcium is safe, and most likely a healthy choice. By choosing to use these you are enabling your body to function properly and correctly. The three different types of calcium all have an important function and are used to boost the natural calcium in your body. These types of calcium can be found in the foods you eat, the drinks you drink, and the dietary supplements you use. Each of these has been found to improve your blood system, your muscles your bones, and your teeth. These are in the simplest form, the same as calcium with the exception that these actually help calcium do it what it needs to do in the body ...
The association of L-type Ca(2+) channels to the secretory granules and its functional significance to secretion was investigated in mouse pancreatic B cells. Nonstationary fluctuation analysis showed that the B cell is equipped with ,500 alpha1(C) L-type Ca(2+) channels, corresponding to a Ca(2+) channel density of 0.9 channels per microm(2). Analysis of the kinetics of exocytosis during voltage-clamp depolarizations revealed an early component that reached a peak rate of 1.1 pFs(-1) (approximately 650 granules/s) 25 ms after onset of the pulse and is completed within approximately 100 ms. This component represents a subset of approximately 60 granules situated in the immediate vicinity of the L-type Ca(2+) channels, corresponding to approximately 10% of the readily releasable pool of granules. Experiments involving photorelease of caged Ca(2+) revealed that the rate of exocytosis was half-maximal at a cytoplasmic Ca(2+) concentration of 17 microM, and concentrations ,25 microM are required to ...
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Crude Protein (Min.)… 14.0%. Lysine (Min.) … 0.75%. Methionine (Min.)… 0.22%. Methionine and Cystine (Min.)… 0.50%. Threonine (Min.) … 0.50%. Crude Fat (Min.) …8.0%. Crude Fiber (Max.) … 20.0%. Calcium (Ca) (Min.) … 0.8%. Calcium (Ca) (Max.) … 1.3%. Phosphorus (P) (Min.) … 0.60%. Copper (Cu) (Min.) …65 ppm. Zinc (Zn) (Min.) … 200 ppm. Selenium (Se) (Min.) … 0.6 ppm. Potassium (K) (Min.)… 1.0%. Magnesium (Mg) (Min.) … 0.35%. Manganese (Mn) (Min.)… 160 ppm. Cobalt (Co) (Min.) … 1.3 ppm. Iron (Fe) (Min.)… 440 ppm. Iodine (I) (Min.)… 1.1 ppm. Salt (NaCI) (Min.) … 0.5%. Salt (NaCI)(Max.) … 1.0%. Vitamin A (Min.) … 5,500 IU/lb.. Vitamin D (Min.) … 500 IU/lb.. Vitamin E (Min.) … 200 IU/lb.. Vitamin C (Min.) … 25 mg/lb.. Biotin (Min.) …0.7 mcg/lb.. Thiamine (Min.) … 8.5 mg/lb.. Riboflavin (Min.) … 4.5 mg/lb.. Omega 6 Fatty Acids (Min.)… 2.8%. Omega 3 Fatty Acids (Min.)… 0.3%. ...
Motivated by the analysis of glomerular time series extracted from calcium-imaging data, asymptotic theory for piecewise polynomial and spline regression with partially free knots and residuals...
We got an assignment to find such three dependent events that satisfy this equation: P(A*B*C)=P(A)*P(B)*P(C). I was thinking to solve this with use of
This is a throwback puzzle to the early days of Foldit. This protein, which inhibits muscle contraction in the absence of calcium ions, changes conformation in the presence of calcium to allow muscle contraction. We are revisiting old Foldit puzzles so we can see how useful the recent additions to the game have been ...
This is a throwback puzzle to the early days of Foldit. This protein, which inhibits muscle contraction in the absence of calcium ions, changes conformation in the presence of calcium to allow muscle contraction. We are revisiting old Foldit puzzles so we can see how useful the recent additions to the game have been ...
Calcium Indicators are small molecules that can chelate calcium ions. All these molecules are based on an EGTA homologue called BAPTA (with exception of coelenterazines), with high selectivity for calcium (Ca) ions versus magnesium (Mg) ions. This group of indicators includes fura-2, indo-1, fluo-3, BTC, Rhod-2, etc. These dyes are generally used with the chelator carboxyl groups masked as acetoxymethyl esters, in order to render the molecule lipophilic and to allow easy entrance into the cell. Once the indicator is in the cell, cellular esterases will free the carboxyl and the indicator will be able to bind calcium.. Fluorescent Chloride Indicators ...
As I was speaking of the dangers of too much Calcium (Ca) in my last post and as excess Ca is lethal, I want to give you an idea of where Ca can land up in our bodies. If it is NOT laid down in our bones as most of it should be, this is what can happen. The following images give an idea of the effects of a Ca overload on your heart and the rest of your body. 99% of Ca should be in your bones with just 1% in your cells, soft tissue and bloodstream. To start, here is a three dimensional CTA data set showing calcifications in coronary arteries. Continue reading Calcium Supplements = Heart Disease →. ...
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For a proper work of the bodily functions, we need to take in proper amounts of electrolytes. When dissolved in water, electrolytes produce electrically-c
- You might have noticed that working out or sweating excessively may leave you feeling tired and dehydrated even when you drink plenty of water. This is bec
A test for calcium in urine is a 24-hour test that checks the amount of calcium that is passed from the body in the urine. Calcium is the most common mineral in the body and one of the most important. The body needs it to build and fix bones and teeth, help nerves work, make muscles squeeze together, help blood clot...
Age dependent changes of cell update markers and endothelial activity related to the involutionary transformations of the skin system, Manturova NE, Kononov AV, Gorodilov RV, Stupi
Predicted to have calcium ion binding activity. Predicted to localize to the endoplasmic reticulum. Is expressed in several structures, including axial mesoderm; chordo neural hinge; epidermis; head; ... Predicted to have calcium ion binding activity. Predicted to localize to the endoplasmic reticulum. Is expressed in several structures, including axial mesoderm; chordo neural hinge; epidermis; head; and pectoral fin. Orthologous to human RCN1 (reticulocalbin 1). ...
TITLE decay of internal calcium concentration : : Internal calcium concentration due to calcium currents and pump. : Differential equations. : : Simple model of ATPase pump with 3 kinetic constants (Destexhe 92) : Cai + P ,-, CaP -, Cao + P (k1,k2,k3) : A Michaelis-Menten approximation is assumed, which reduces the complexity : of the system to 2 parameters: : kt = ,tot enzyme concentration, * k3 -, TIME CONSTANT OF THE PUMP : kd = k2/k1 (dissociation constant) -, EQUILIBRIUM CALCIUM VALUE : The values of these parameters are chosen assuming a high affinity of : the pump to calcium and a low transport capacity (cfr. Blaustein, : TINS, 11: 438, 1988, and references therein). : : Units checked using modlunit -, factor 10000 needed in ca entry : : VERSION OF PUMP + DECAY (decay can be viewed as simplified buffering) : : All variables are range variables : : : This mechanism was published in: Destexhe, A. Babloyantz, A. and : Sejnowski, TJ. Ionic mechanisms for intrinsic slow oscillations in : ...
TITLE decay of internal calcium concentration : : Internal calcium concentration due to calcium currents and pump. : Differential equations. : : Simple model of ATPase pump with 3 kinetic constants (Destexhe 92) : Cai + P ,-, CaP -, Cao + P (k1,k2,k3) : A Michaelis-Menten approximation is assumed, which reduces the complexity : of the system to 2 parameters: : kt = ,tot enzyme concentration, * k3 -, TIME CONSTANT OF THE PUMP : kd = k2/k1 (dissociation constant) -, EQUILIBRIUM CALCIUM VALUE : The values of these parameters are chosen assuming a high affinity of : the pump to calcium and a low transport capacity (cfr. Blaustein, : TINS, 11: 438, 1988, and references therein). : : Units checked using modlunit -, factor 10000 needed in ca entry : : VERSION OF PUMP + DECAY (decay can be viewed as simplified buffering) : : All variables are range variables : : : This mechanism was published in: Destexhe, A. Babloyantz, A. and : Sejnowski, TJ. Ionic mechanisms for intrinsic slow oscillations in : ...
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Impairment of GABA release due to reduction of VGAT in μ3B−/−ΔNeo mice. (A and B) Measurement of glutamate (A) and GABA (B) release was performed as descr
Yes, too much protein is bad for your body just like consuming too many carbs or fats. But instead of giving you extra calories for fat gains, the bad portion is actually worse than you think.. When we have too much protein in our body it decreases the absorption of calcium, which in the end could cause calcium deficiency. If you dont know what that means simply think weaker or even fragile bones.. This is one of the reasons why bodybuilders and other athletes are precise with their nutrient intake. Surely a little extra protein isnt going to do much harm, but LOTS of people get carried away with their protein supplements.. (NOTE: If you need help with this I offer affordable monthly online meal programs). Add the extra protein if you need more calories for muscle gains, but dont get carried away with it for extended duration.. Our thoughts on Protein Supplements. Protein supplements only aid in your quest for proper nutrient intake, but should not be consumed to replace a meal more than once ...
Minerals: magnesium and calcium are essential for healthy heart. Calcium triggers the contraction and relaxation of the heart (all muscles) while Mg is important to be in the right ratio as calcium for calcium to work or else irregular heartbeats (sign of Mg deficiencies). Try using EPSOM GEL daily as your "skin is a mouth" to absorb the magnesium directly into the skin ...
Metamucil Multihealth Fiber Capsules with Calcium - Metamucil® Multihealth Fiber Capsules Plus Calcium give you healthy fiber and are an exce
The 5th European Seminar in Virology (EuSeV) will be held in Bertinoro from 16 to 18 june. These are short meetings, organized by the European Society for Virology (ESV) (http://www.eusv.eu), dedicate
Ca2+ ions are unique in that they not only carry charge but they are also the most widely used of diffusible second messengers. Voltage-dependent Ca2+ channels (VDCC) are a family of molecules that allow cells to couple electrical activity to intracellular Ca2+ signalling. The opening and closing of these channels by depolarizing stimuli, such as action potentials, allows Ca2+ ions to enter neurons down a steep electrochemical gradient, producing transient intracellular Ca2+ signals. Many of the processes that occur in neurons, including transmitter release, gene transcription and metabolism are controlled by Ca2+ influx occurring simultaneously at different cellular locales. The pore is formed by the alpha-1 subunit which incorporates the conduction pore, the voltage sensor and gating apparatus, and the known sites of channel regulation by second messengers, drugs, and toxins [(PUBMED:14657414)]. The activity of this pore is modulated by four tightly-coupled subunits: an intracellular beta ...
Calcium is good for your bones and teeth as well as essential to the workings of your nervous system, muscle contractions, and blood vessel expansion. Determining how to eat more calcium can allow you to lead the healthy lifestyle you have always wanted.
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1GJY: The Crystal Structure of the Sorcin Calcium Binding Domain Provides a Model of Ca(2+)-Dependent Processes in the Full-Length Protein
I was wondering why would RHEL use swap , when there are Free buffers (shown in free command) In our case when we see free memory in top command getting exhausted, The server is using SWAP even...
Not having enough calcium can cause many health problems. Calcium insufficiency also causes weak bones and tooth decay. This is because almost all calcium is stored in bones and teeth.
ISCHAEMIA AND INCREASED LEFT VENTRICULAR WALL TENSION. An increase in intracellular sodium (Na) is an early event during myocardial ischemia1. Increased Na concentration in the myocardium leads to calcium (Ca++) overload as a result of decreased efflux ...
Can you find Nitroblastx in stores? The answer is yes, in some stores. When you first encounter Nitroblastx in stores, you will think it couldnt do all it
Asher is recovering well so far but is not out of the woods yet. He still needs to recover from the surgery and its in the recovery phase that they expect the most amount of complications. His edema/swelling has come back (this is expected after major surgery) and his urine output has slowed down a bit. His blood pressure has been running a bit high. He is doing pretty good but still is in need of your prayers for him to fully recover. His calcium levels are low and they say that this is not only expected during this type of surgery but could also be attributed to the possible Chromosome Syndrome he has. We need to continue to pray that no infection would take place. They are talking about closing his chest tomorrow as long as he looses a bit more edema and everything is functioning right with his heart. The incision has been open since yesterday and looks really intense. It makes Erika and I woozy after a few minutes being around him. Its covered by a semi-see through material and you can see ...
Hi folks. Just had full panel of bloods done. Total serum calcium is just slightly high and corrected calcium slightly low. B12 is 1083. Vitamin d 38, and ferretin 13. Having headaches fatigue...
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I dont have all your data to make an appropriate conclusion. It would be helpful to have the CD4 absolute count and percentages for all your tests to see what the trend is. The CD4 percent is a...
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B Cell小鼠单克隆抗体[CA2.1D6](ab34125)可与马, 猫样本反应并经IP, IHC, Flow Cyt实验严格验证,被3篇文献引用。所有产品均提供质保服务,中国75%以上现货。
This file defines the functional laboratory areas. Each area may have multiple accession areas. Entries may be added, but supplied entries should not be modified or deleted. It is pointed to by the COLLECTION SAMPLE and ACCESSION TEST GROUP files ...
Specifies one of three states for the widget: normal, readonly, or disabled. If the widget is disabled then the value may not be changed and the arrow button wont activate. If the widget is readonly, the entry may not be edited, but it may be changed by choosing a value from the popup listbox. normal is the default.. ...
The Sanjay Dutt, Bipasha Basu, Kunal Kapoor starrer Lamhaa, which is directed by Rahul Dholakia and produced by Bunty Walia, is ready for release.
There are quite a few limited releases on this weeks list, include a few that are opening in dozens of theaters. Freakonomics is generating the most
New Delhi: June 18, 2016: Calcium is important for maintaining strong bones. It also helps in blood clotting, early developmental growth and muscle contraction and relaxation. Calcium can be easily obtained from natural food sources like leafy vegetables, yoghurt, nuts and cheese. However, the majority of the Indians, specifically in the age group of 14-20 years suffer from calcium deficiency due to lack of efficient absorption. "Calcium deficiency disease, also known as hypocalcemia, occurs when you dont get enough calcium. It is crucial that people are educated about the effects of calcium deficiency on the overall health and wellbeing of people in the long run. Those suspected of suffering from calcium deficiency should not self-diagnose and treat themselves by consuming large amounts of calcium supplements. Instead, it is important that they consult their doctor and together devise a healthy eating plan supported by supplementation," said Padma Shri Awardee Dr KK Aggarwal - Honorary ...
Aequorin, which luminesces in the presence of calcium, was injected into photoreceptor cells of Limulus ventral eye. A bright light stimulus elicited a large increase in aequorin luminescence, the aequorin response, indicating a rise of intracellular calcium ion concentration, Cai. The aequorin response reached a maximum after the peak of the electrical response of the photoreceptor, decayed during a prolonged stimulus, and returned to an undetectable level in the dark. Reduction of Cao reduced the amplitude of the aequorin response by a factor no greater than 3. Raising Cao increased the amplitude of the aequorin response. The aequorin response became smaller when membrane voltage was clamped to successively more positive values. These results indicate that the stimulus-induced rise of Cai may be due in part to a light-induced influx of Ca and in part to release of Ca from an intracellular store. Our findings are consistent with the hypothesis that a rise in Cai is a step in the sequence of ...
TY - JOUR. T1 - Intracellular free calcium increases in cultured cortical neurons deprived of oxygen and glucose.. AU - Goldberg, M. P.. AU - Choi, D. W.. PY - 1990/11/1. Y1 - 1990/11/1. N2 - Dissociated neocortical cultures from fetal mice exposed transiently to a medium lacking both glucose and oxygen developed neuronal degeneration without glial degeneration. We have found that this injury depends on extracellular calcium and is associated with uptake of calcium from the culture medium. We measured free cytoplasmic calcium in individual neurons using the fluorescent calcium indicator fluo-3 and provide evidence that oxygen and glucose deprivation injury increases the intracellular calcium signal. Both intracellular calcium elevation and subsequent neuronal loss could be blocked by the N-methyl-D-aspartate receptor antagonist dextrorphan.. AB - Dissociated neocortical cultures from fetal mice exposed transiently to a medium lacking both glucose and oxygen developed neuronal degeneration ...
In previous efforts to characterize sarcoplasmic reticulum function in human muscles, it has not been possible to distinguish the relative contributions of fast-twitch and slow-twitch fibers. In this study, we have used light scattering and 45Ca to monitor Ca accumulation by the sarcoplasmic reticulum of isolated, chemically skinned human muscle fibers in the presence and absence of oxalate. Oxalate (5 mM) increased the capacity for Ca accumulation by a factor of 35 and made it possible to assess both rate of Ca uptake and relative sarcoplasmic reticulum volume in individual fibers. At a fixed ionized Ca concentration, the rate and maximal capacity (an index of sarcoplasmic reticulum volume) both varied over a wide range, but fibers fell into two distinct groups (fast and slow). Between the two groups, there was a 2- to 2.5-fold difference in oxalate-supported Ca uptake rates, but no difference in average sarcoplasmic reticulum volumes. Intrinsic differences in sarcoplasmic reticulum function ...
Calcium is an essential mineral for several important functions in the body of an animal. Calcium is needed for the development of the fetal skeleton as well as for the secretion of milk in lactating females, making pregnant and nursing guinea pigs more prone to calcium deficiency if their increased nutritional needs are not being met. This related type of calcium deficiency usually develops in the one to two weeks before, or shortly after, giving birth. Also at higher risk of calcium deficiency are obese or stressed guinea pigs, or guinea pigs that have already been pregnant several times.
TY - JOUR. T1 - Stimulation of d2 dopamine receptors decreases intracellular calcium levels in rat anterior pituitary cells but not striatal synaptosomes. T2 - A flow cytometric study using indo‐1. AU - Wolf, Marina E.. AU - Kapatos, Gregory. PY - 1989. Y1 - 1989. N2 - An important question is whether all D2 dopamine (DA) receptors employ the same signal transduction mechanisms. Anterior pituitary cells and striatal synaptosomes, which possess pharmacologically similar D2 DA receptors, were compared with respect to the effect of D2 DA receptor stimulation on free intracellular Ca2+ levels ([Ca2+]i). Flow cytometry, in combination with either the fluorescent calcium indicator indo‐1 or fluorescent voltage‐sensitive dyes, was used to measure [Ca2+]i and to detect changes in membrane potential. In subpopulations of anterior pituitary cells, increases in [Ca2+]i were produced by elevated K+, veratridine, thyrotropin‐releasing hormone, and BAY K 8644. These increases were blocked by ...
Cellular stress responses often involve elevation of cytosolic calcium levels, and this has been suggested to stimulate autophagy. Here, however, we demonstrated that agents that alter intracellular calcium ion homeostasis and induce ER stress-the calcium ionophore A23187 and the sarco/endoplasmic reticulum Ca (2+)-ATPase inhibitor thapsigargin (TG)-potently inhibit autophagy. This anti-autophagic effect occurred under both nutrient-rich and amino acid starvation conditions, and was reflected by a strong reduction in autophagic degradation of long-lived proteins. Furthermore, we found that the calcium-modulating agents inhibited autophagosome biogenesis at a step after the acquisition of WIPI1, but prior to the closure of the autophagosome. The latter was evident from the virtually complete inability of A23187- or TG-treated cells to sequester cytosolic lactate dehydrogenase. Moreover, we observed a decrease in both the number and size of starvation-induced EGFP-LC3 puncta as well as reduced numbers of