Half Cell Potentials
Mostrando 13-24 de 186 artigos, teses e dissertações.
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13. Inactivation characteristics reveal two calcium currents in adult bovine chromaffin cells.
1. Two calcium currents were identified by differences in their inactivation characteristics in adult chromaffin cells maintained in short-term primary culture (3-5 days). Calcium currents were recorded by means of the whole-cell configuration using an intracellular medium highly buffered for pH and pCa. 2. Calcium current evoked from a holding potential of
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14. Local control of excitation-contraction coupling in rat heart cells.
1. Cytosolic free calcium ion concentration ([Ca2+]i) and whole-cell L-type Ca2+ channel currents were measured during excitation-contraction (E-C) coupling in single voltage-clamped rat cardiac ventricular cells. The measurements were used to compute the total cellular efflux of calcium ions through sarcoplasmic reticulum (SR) Ca2+ release channels (FSR,rel
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15. Whole-cell K+ currents in identified olfactory bulb output neurones of rats.
1. Voltage-gated whole-cell K+ currents have been investigated in olfactory bulb (OB) output (mitral/tufted) neurones from neonatal rats, which were retrogradely labelled by rhodamine or Fast Blue and identified after enzymatic dissociation. Forty-five per cent of labelled neurones exhibited either phasic or non-phasic spontaneous firing in cell-attached con
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16. Slow depolarizing and hyperpolarizing currents which mediate bursting in Aplysia neurone R15.
Interruption of normal bursting activity by application of a voltage clamp reveals that action potentials in Aplysia neurone R15 are followed by two slow currents that long outlast the currents produced during the action potentials. Similar currents are seen following simulation of an action potential with a brief depolarizing pulse delivered under continuou
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17. Dependence of Na+ pump current on external monovalent cations and membrane potential in rabbit cardiac Purkinje cells.
1. The effect of membrane potential and various extracellular monovalent cations on the Na+ pump current (Ip) was studied on isolated, single Purkinje cells of the rabbit heart by means of whole-cell recording. 2. Ip was identified as current activated by external K+ or its congeners NH4+ and Tl+. The current was blocked by dihydroouabain (1-5 x 10(-4) M) ov
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18. Na+ pump current-voltage relationships of rabbit cardiac Purkinje cells in Na(+)-free solution.
1. The Na+ pump current (Ip) of isolated, single rabbit cardiac Purkinje cells in Na(+)-free solution was measured at 32-34 degrees C by means of whole-cell recording. 2. The Ip amplitude was studied as a function of clamp potential (Vc) and external concentration of various monovalent cations known to activate the Na(+)-K+ pump. 3. Under conditions which st
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19. Chloride currents of single mitochondria-rich cells of toad skin epithelium.
1. Mitochondria-rich (MR) cells in free suspension were obtained by collagenase and trypsin treatments of toad skin epithelium and studied by whole-cell voltage clamp and membrane current fluctuation analysis. 2. Cells studied with a 100 microM amiloride and 5 mM Ba2+ Ringer solution on the outside and 10 mM Cs+ in the pipette generated large membrane curren
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20. Electrophysiological properties of neurones in the region of the paraventricular nucleus in slices of rat hypothalamus.
1. Neurones in the region of the hypothalamic paraventricular nucleus (PVN) of the rat were studied with intracellular recording in the coronal slice preparation. Three types of hypothalamic neurones were distinguished according to their membrane properties and anatomical positions. Lucifer Yellow or ethidium bromide was injected intracellularly to determine
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21. Kinetic analysis of voltage- and ion-dependent conductances in saccular hair cells of the bull-frog, Rana catesbeiana.
1. By the use of whole-cell and excised-patch tight-seal recording techniques, we studied ionic conductances in voltage-clamped solitary hair cells isolated from the bull-frog's sacculus. As a basis for assessing their contributions to hair cell electrical resonance, we developed kinetic models describing voltage-dependent Ca2+ and Ca2+-dependent K+ conducta
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22. A patch-clamp study of mammalian platelets and their voltage-gated potassium current.
1. Mammalian platelets were freshly isolated from human, rabbit, or rat blood. The whole-cell and cell-attached voltage-clamp variations of the patch-clamp technique were employed to study the passive electrical properties and ion channels of unstimulated platelets. 2. The input capacitance of a platelet measured by the phase-sensitive detection method was a
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23. Inactivation, reactivation and pacing dependence of calcium current in frog cardiocytes: correlation with current density.
1. Ca2+ currents were measured in single cells isolated from frog ventricle using the whole-cell patch clamp technique and a perfused pipette. K+ currents were blocked with intracellular (120 mM) and extracellular (20 mM) Cs+. 2. A single type of Ca2+ current (ICa) was found in these cells. The current activated at voltages positive to -30 mV, exhibited a sy
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24. Comparison of ionic currents from interstitial cells and smooth muscle cells of canine colon.
1. Voltage-dependent ionic currents of isolated interstitial cells were characterized using the whole-cell voltage clamp technique, and compared with currents recorded from circular muscle cells. Both cell types were isolated from the submucosal pacemaking region in the canine distal colon. 2. Upon depolarization, interstitial cells and smooth muscle cells g