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| Registros recuperados: 149 | |
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| MACKENZIE,LAUREN; RODERICK,H. LLEWELYN; PROVEN,ANDREW; CONWAY,STUART J; BOOTMAN,MARTIN D. |
| Inositol 1,4,5-trisphosphate (InsP3) is an established calcium-mobilizing messenger, which is well-known to activate Ca2+ signaling in many cell types. Contractile cardiomyocytes express hormone receptors that are coupled to the production of InsP3. Such cardioactive hormones, including endothelin, may have profound inotropic and arrhythmogenic actions, but it is unclear whether InsP3 underlies any of these effects. We have examined the expression and localization of InsP3 receptors (InsP3Rs), and the potential role of InsP3 in modulating cardiac excitation-contraction coupling (EC coupling). Stimulation of electrically-paced atrial and ventricular myocytes with a membrane-permeant InsP3 ester was found to evoke an increase in the amplitudes of action... |
| Tipo: Journal article |
Palavras-chave: Calcium; Cardiac; Inositol; Arrhythmia; Ryanodine. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400008 |
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| WILLIAMS,ALAN J; TANNA,BHAVNA. |
| Ryanodine binds with high affinity and specificity to a class of Ca2+-release channels known as ryanodine receptors (RyR). The interaction with RyR results in a dramatic alteration in function with open probability (Po) increasing markedly and rates of ion translocation modified. We have investigated the features of ryanodine that govern the interaction of the ligand with RyR and the mechanisms underlying the subsequent alterations in function by monitoring the effects of congeners and derivatives of ryanodine (ryanoids) on individual RyR2 channels. While the interaction of all tested ryanoids results in an increased Po, the amplitude of the modified conductance state depends upon the structure of the ryanoid. We propose that different rates of cation... |
| Tipo: Journal article |
Palavras-chave: Calcium; Ca2+-release channel; Sarcoplasmic reticulum; Ryanodine; Single channel. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400006 |
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| MUÑOZ,PABLO; ZAVALA,GABRIELA; CASTILLO,KAREN; AGUIRRE,PABLA; HIDALGO,CECILIA; NÚÑEZ,MARCO T. |
| Recent evidence suggests that reactive oxygen species function as second messenger molecules in normal physiological processes. For example, activation of N-Methyl-D-Aspartate receptor results in the production of ROS, which appears to be critical for synaptic plasticity, one of the cellular mechanisms that underlie learning and memory. In this work, we studied the effect of iron in the activation of MAPK/ERK pathway and on Ca2+ signaling in neuronal PC12 cells. We found that iron-dependent generation of hydroxyl radicals is likely to modulate Ca2+ signaling through RyR calcium channel activation, which, in turn, activates the MAPK/ERK pathway. These findings underline the relevance of iron in normal neuronal function. |
| Tipo: Journal article |
Palavras-chave: NMDA receptor; Calcium; Iron; Oxidative stress; MAPK/ERK; Hippocampal slices; Long-term potentiation. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000100021 |
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| Wang,Hui; Liu,Zheng; Zhang,Wenxiu; Yuan,Ziao; Yuan,Hongyi; Liu,Xueting; Yang,Chunwen; Guan,Weijun. |
| BACKGROUND: Heavy metals can cause great harm to Siberian tigers in the natural environment. Cadmium (Cd2+) is an environmental contaminant that affects multiple cellular processes, including cell proliferation, differentiation, and survival. It has been shown to induce apoptosis in a variety of cell types and tissues. RESULTS: We investigated the apoptotic effects of Cd2+ on Siberian tiger fibroblasts in vitro. Our research revealed the typical signs of apoptosis after Cd²+ exposure. Apoptosis was dose- (0-4.8 μΜ) and duration-dependent (12-48 h), and proliferation was strongly inhibited. Cd²+ increased the activity of caspase-3, -8, and -9 and disrupted calcium homeostasis by causing oxidative stress and mitochondrial dysfunction. It... |
| Tipo: Journal article |
Palavras-chave: Siberian tiger; Cadmium; Apoptosis; Fibroblast; Calcium. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602016000100042 |
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| LANZA,HENRIQUE; AFONSO-CARDOSO,SANDRA R; SILVA,ADRIANO G; NAPOLITANO,DANIELLE R; ESPÍNDOLA,FOUED S; PENA,JANETHE D.O; SOUZA,MARIA A. |
| Amastigotes of Leishmania major have a great ability to evade destruction in host cells. This study investigated the activation in resident, inflammatory macrophages and J774 cells in vitro treated with lipopolysaccharide (LPS), soluble Leishmania antigen (SLA), calcium ionophore (CaI) and magnesium (Mg2+) alone or combined. An increase in nitric oxide (NO) production was observed in J774 or inflammatory macrophages treated with LPS alone or in combination with SLA and CaI. The same treatments did not affect the NO release by resident macrophages. There was no interference in uptake of L. major but CaI decreased intracellular proliferation of the parasite. This study demonstrated the importance of CaI in decreasing L. major proliferation inside murine... |
| Tipo: Journal article |
Palavras-chave: Calcium; Leishmania major; Macrophage; Magnesium; Nitric oxide. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000300004 |
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| Foskett,J. Kevin; Mak,D.-O. Daniel. |
| The InsP3R Ca2+-release channel has biphasic dependence on cytoplasmic free Ca2+ concentration ([Ca2+]i). InsP3 activates gating primarily by reducing high [Ca2+]i inhibition. To determine whether relieving Ca2+ inhibition is sufficient for activation, we examined single-channels in low [Ca2+]i in the absence of InsP3 by patch clamping isolated Xenopus oocyte nuclei. For both endogenous Xenopus type 1 and recombinant rat type 3 InsP3R channels, spontaneous InsP3-independent activities with low open probability Po (~ 0.03) were observed in [Ca2+]i < 5 nM, whereas none were observed in 25 nM Ca2+. These results establish the half-maximal inhibitory [Ca2+]i in the absence of InsP3 and demonstrate that the channel can be active when all of its... |
| Tipo: Journal article |
Palavras-chave: InsP3 receptor; Calcium release channel; Calcium; Ion channel; Model. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400004 |
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| Corrêa,Thais Roseli; Steffens,Cristiano André; Amarante,Cassandro Vidal Talamini do; Miqueloto,Aquidauana; Brackmann,Auri; Ernani,Paulo Roberto. |
| ABSTRACT Flesh browning is a physiological disorder that occurs in ‘Fuji’ apples during storage, which causes considerable postharvest losses of fruit produced in Southern Brazil. This work aimed to assess the mineral attributes [Ca; Mg and K contents and the Mg/Ca; K/Ca and (K + Mg)/Ca ratios] associated with the flesh browning disorder incidence, as well as to identify which of these mineral attributes better discriminate the differences in the degree of susceptibility to flesh browning disorder in ‘Fuji’ apples stored under controlled atmosphere (CA; 1.2 kPa O2 + 2.0 kPa CO2 and 1.2 kPa O2 + < 0.5 kPa CO2; 0.5 ± 0.1 °C and 96 ± 2% RH, during an 8-month period). Apples from 2 orchards in Fraiburgo, Santa Catarina, 3 orchards in São Joaquim, Santa... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Malus domestica; Physiological disorder; Canonical discriminant analysis; Calcium. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052017000200327 |
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| Rosolem,Ciro Antonio. |
| In this work, a greenhouse experiment was conducted to study the effects of N fertilization and residues of pearl millet, black oats and oilseed radish on pH and Ca, Mg, K, NO3-, and NH4+ distribution within the profile of a Distroferric Red Latosol. The equivalent of 8 t ha-1 of plant residues were placed on soil surface. Lime was applied on the soil surface and nitrogen was applied over the straw at 0, 50, 100, and 150 mg kg-1, as ammonium nitrate. Corn was grown for 57 days. Calcium contents and pH in the soil profile were decreased by Pearl millet residue, while black oat and oilseed radish increased Ca contents and these effects are not related with Ca contents in residue tissue. However, the presence of plant residues increased nitrate, ammonium, and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calcium; Magnesium; Nitrogen; Potassium; Soil bases; No till. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000300003 |
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| Huaynate,Rizal Alcides Robles; Thomaz,Maria Cristina; Kronka,Rodolfo Nascimento; Fraga,Alessandro Luís; Scandolera,Antônio João; Budiño,Fábio Enrique Lemos. |
| This study aimed to verify the effect of diets with different doses (0, 100, 200 and 300 ppm) of probiotic on daily fecal production (DFP) and level of macro and micro minerals in feces of nursing (1st and 2nd initial phases) and growing pigs and during total period. The DFP, as percentage of body weight, was different (P<0.05) among treatments only at 1st initial phase. Fecal levels of macro and micro minerals were similar (P>0.05) among treatments, with exception of calcium and sodium excretion at 1st initial phase and calcium, zinc and nickel during total period. The addition of a poliprobiotic to diets do not affect fecal production of nursing and growing pigs. However, the presence of microorganisms, added (levels of 200 and 300 ppm) in diets... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calcium; Digestion; Lactobacillus; Piglet; Zinc. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000400005 |
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| Sartorello,R.; Garcia,C.R.S.. |
| An increasing number of pathophysiological roles for purinoceptors are emerging, some of which have therapeutic potential. Erythrocytes are an important source of purines, which can be released under physiological and physiopathological conditions, acting on purinergic receptors associated with the same cell or with neighboring cells. Few studies have been conducted on lizards, and have been limited to ATP agonist itself. We have previously shown that the red blood cells (RBCs) of the lizard Ameiva ameiva store Ca2+ in the endoplasmic reticulum (ER) and that the purinergic agonist ATP triggers a rapid and transient increase of [Ca2+]c by mobilization of the cation from internal stores. We also reported the ability of the second messenger IP3 to discharge... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Red blood cells; Calcium; Teiidae; Ameiva ameiva; Purinoceptor; UTP. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000100002 |
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| Isolated segments of the perfused rat tail artery display a high basal tone when compared to other isolated arteries such as the mesenteric and are suitable for the assay of vasopressor agents. However, the perfusion of this artery in the entire tail has not yet been used for functional studies. The main purpose of the present study was to identify some aspects of the vascular reactivity of the rat tail vascular bed and validate this method to measure vascular reactivity. The tail severed from the body was perfused with Krebs solution containing different Ca2+ concentrations at different flow rates. Rats were anesthetized with sodium pentobarbital (65 mg/kg) and heparinized (500 U). The tail artery was dissected near the tail insertion, cannulated and... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Rat tail vascular bed; Phenylephrine; Calcium; Flow; Endothelium; Vascular tone; Perfusion pressure. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000700012 |
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| Wang,Gui-Jun; Wang,Hong-Xin; Yao,Yu-Sheng; Guo,Lian-Yi; Liu,Pei. |
| We investigated whether Ca2+/calmodulin-dependent kinase II (CaMKII) and calcineurin (CaN) are involved in myocardial hypertrophy induced by tumor necrosis factor α (TNF-α). The cardiomyocytes of neonatal Wistar rats (1-2 days old) were cultured and stimulated by TNF-α (100 μg/L), and Ca2+ signal transduction was blocked by several antagonists, including BAPTA (4 µM), KN-93 (0.2 µM) and cyclosporin A (CsA, 0.2 µM). Protein content, protein synthesis, cardiomyocyte volumes, [Ca2+]i transients, CaMKIIδB and CaN were evaluated by the Lowry method, [³H]-leucine incorporation, a computerized image analysis system, a Till imaging system, and Western blot analysis, respectively. TNF-α induced a significant increase in protein content in a dose-dependent manner... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Myocardial hypertrophy; Tumor necrosis factor α; Calcium; Calmodulin-dependent kinase; Calcineurin. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001100008 |
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| Srivastav,S.K.; Srivastav,A.K.. |
| Adult Channa punctatus murrels of both sexes (60-80 g) were collected locally from Ramgarh Lake during the second week of every month (10 individuals of each sex/month) throughout the year. Blood samples were collected and analyzed for serum calcium and phosphate levels by the methods of Trinder (1960) and Fiske and Subbarow (1925), respectively. Gonads were fixed to judge the state of maturation of the fish. Males exhibited no change in serum calcium levels throughout the year in correlation with testicular maturation. However, serum phosphate levels exhibited a rise in correlation with the increased gonadosomatic index. Females showed marked seasonal changes in serum calcium and phosphate levels which were associated with ovarian maturation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calcium; Inorganic phosphate; Reproduction; Teleost; Vitellogenesis. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000800006 |
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| Registros recuperados: 149 | |
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