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	Provedor de dados Biol. Res. (2) BJMBR (1) Autor Foskett,J. Kevin (1) MEARS,DAVID (1) Mak,D.-O. Daniel (1) ROJAS,EDUARDO (1) Salomão,L.C. (1) Schwartz,C.A. (1) Schwartz,E.F. (1) Stucchi-Zucchi,A. (1) Mais... Palavra-chave Ion channel (3) BAPTA (1) Calcium (1) Calcium release channel (1) Channel-forming toxins (1) Hemolysin (1) Inactivation kinetics (1) InsP3 receptor (1) Insulin (1) Islet of Langerhans (1) Model (1) Siphonops (1) Skin secretion (1) Stimulus-secretion coupling (1) Toxin (1) Mais... Tipo do documento Journal article (2) Info:eu-repo/semantics/other (1) Ano 2006 (1) 2004 (1) 2003 (1) País Chile (2) Brazil (1) Idioma Inglês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 Primeira ... 1 ... Última Novel model of calcium and inositol 1,4,5-trisphosphate regulation of InsP3 receptor channel gating in native endoplasmic reticulum Biol. Res. 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 Properties of voltage-gated Ca2+ currents measured from mouse pancreatic &#946;-cells in situ Biol. Res. MEARS,DAVID; ROJAS,EDUARDO. We used the single-microelectrode voltage-clamp technique to record ionic currents from pancreatic &#946;-cells within intact mouse islets of Langerhans at 37C, the typical preparation for studies of glucose-induced "bursting" electrical activity. Cells were impaled with intracellular microelectrodes, and voltage pulses were applied in the presence of tetraethylammonium. Under these conditions, a voltage-dependent Ca2+ current (I Cav), containing L-type and non-L-type components, was observed. The current measured in situ was larger than that measured in single cells with whole-cell patch clamping, particularly at membrane potentials corresponding to the action potentials of &#946;-cell electrical activity. The temperature dependence of I Cav was... Tipo: Journal article Palavras-chave: Islet of Langerhans; Insulin; Stimulus-secretion coupling; Ion channel; Inactivation kinetics; BAPTA. Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000300012 Skin secretion of Siphonops paulensis (Gymnophiona, Amphibia) forms voltage-dependent ionic channels in lipid membranes BJMBR Schwartz,E.F.; Stucchi-Zucchi,A.; Schwartz,C.A.; Salomão,L.C.. The effect of the skin secretion of the amphibian Siphonops paulensis was investigated by monitoring the changes in conductance of an artificial planar lipid bilayer. Skin secretion was obtained by exposure of the animals to ether-saturated air, and then rinsing the animals with distilled water. Artificial lipid bilayers were obtained by spreading a solution of azolectin over an aperture of a Delrin cup inserted into a cut-away polyvinyl chloride block. In 9 of 12 experiments, the addition of the skin secretion to lipid bilayers displayed voltage-dependent channels with average unitary conductance of 258 ± 41.67 pS, rather than nonspecific changes in bilayer conductance. These channels were not sensitive to... Tipo: Info:eu-repo/semantics/other Palavras-chave: Siphonops; Toxin; Channel-forming toxins; Skin secretion; Ion channel; Hemolysin. Ano: 2003 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000900020 Registros recuperados: 3 Primeira ... 1 ... Última

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