Ionic Relations of Cells of Chara Australis IX. Analysis of Transient Membrane Currents

1964 ◽  
Vol 17 (2) ◽  
pp. 400 ◽  
Author(s):  
GP Findlay ◽  
AB Hope
Keyword(s):  
Voltage Clamp ◽  
Divalent Cations ◽  
Chloride Ion ◽  
Membrane Currents ◽  
Transient Current ◽  
Ion Concentration ◽  
Chara Australis ◽  
Strontium Ions ◽  
Ionic Relations ◽  
High Chloride

The effect of divalent cations and of high chloride ion concentration on voltage-clamp currents in the plasmalemma of O. australis was investigated. Either calcium or strontium ions were necessary in the medium for a transient current to appear during a voltage clamp_ The transient current with strontium was about 20% of that with calcium present. Barium. cadmium, magnesium, manganous, or nickelous ions were unable to replace calcium in. this function.

scholarly journals Ionic Relations of Cells of Chara Australis VIII. Membrane Currents During a Voltage Clamp

1964 ◽  
Vol 17 (2) ◽  
pp. 388 ◽  
Author(s):  
GP Findlay
Keyword(s):  
Membrane Potential ◽  
Action Potential ◽  
Detailed Analysis ◽  
Voltage Clamp ◽  
Membrane Currents ◽  
Voltage Clamps ◽  
Transient Activity ◽  
Predetermined Level ◽  
Chara Australis ◽  
Ionic Relations

Experiments are described in which "voltage clamps" were applied to the "membrane" of O. australis cells comprising tonoplast and plasmalemma and also to the plasmalemma alone. The voltage-clamp system maintained the membrane potential at a predetermined level, and enabled a detailed analysis to be made of the transient electrical phenomena occurring during the action potential. A scarming technique is also described, by means of which the membrane currentpotential characteristics could be determined at any particular time during the transient activity of the membrane.

A calcium-dependent transient outward current in Xenopus laevis oocytes

1982 ◽  
Vol 215 (1201) ◽  
pp. 491-497 ◽  
Keyword(s):  
Membrane Potential ◽  
Xenopus Laevis ◽  
Voltage Clamp ◽  
Outward Current ◽  
Membrane Currents ◽  
Transient Current ◽  
Transient Outward Current ◽  
Xenopus Laevis Oocytes ◽  
Calcium Dependent

Membrane currents were investigated in Xenopus laevis oocytes under voltage clamp. Depolarizing pulses, given from a holding potential of about –100 mV, elicited a transient outward current when the membrane potential was made more positive than about –20 mV. As the potential was made increasingly positive the transient outward current first increased and then decreased. The amplitude of the transient current increased when the external Ca 2+ concentration was raised; and the current was abolished by Mn 2+ . It appears that when the membrane is depolarized Ca 2+ ions enter the oocyte and trigger an outward current, possibly by opening Cl – channels.

scholarly journals First Attempts of the Use of 195Pt NMR of Phenylbenzothiazole Complexes as Spectroscopic Technique for the Cancer Diagnosis

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3970 ◽  
Author(s):  
Bruna T. L. Pereira ◽  
Mateus A. Gonçalves ◽  
Daiana T. Mancini ◽  
Kamil Kuca ◽  
Teodorico C. Ramalho
Keyword(s):  
Cancer Treatment ◽  
Cancer Diagnosis ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chloride Ion ◽  
Platinum Complexes ◽  
Dft Method ◽  
Ion Concentration ◽  
Implicit Solvent ◽  
Early Cancer Diagnosis

Platinum complexes have been studied for cancer treatment for several decades. Furthermore, another important platinum characteristic is related to its chemical shifts, in which some studies have shown that the 195Pt chemical shifts are very sensitive to the environment, coordination sphere, and oxidation state. Based on this relevant feature, Pt complexes can be proposed as potential probes for NMR spectroscopy, as the chemical shifts values will be different in different tissues (healthy and damaged) Therefore, in this paper, the main goal was to investigate the behavior of Pt chemical shifts in the different environments. Calculations were carried out in vacuum, implicit solvent, and inside the active site of P13K enzyme, which is related with breast cancer, using the density functional theory (DFT) method. Moreover, the investigation of platinum complexes with a selective moiety can contribute to early cancer diagnosis. Accordingly, the Pt complexes selected for this study presented a selective moiety, the 2-(4′aminophenyl)benzothiazole derivative. More specifically, two Pt complexes were used herein: One containing chlorine ligands and one containing water in place of chlorine. Some studies have shown that platinum complexes coordinated to chlorine atoms may suffer hydrolyses inside the cell due to the low chloride ion concentration. Thus, the same calculations were performed for both complexes. The results showed that both complexes presented different chemical shift values in the different proposed environments. Therefore, this paper shows that platinum complexes can be a potential probe in biological systems, and they should be studied not only for cancer treatment, but also for diagnosis.

scholarly journals Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Radoń ◽  
Dariusz Łukowiec ◽  
Patryk Włodarczyk
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Chloride Ion ◽  
Ion Source ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Broadband Dielectric Spectroscopy ◽  
Free Chloride ◽  
Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

scholarly journals Membrane currents elicited by divalent cations in Xenopus oocytes.

1989 ◽  
Vol 417 (1) ◽  
pp. 173-195 ◽  
Author(s):  
R Miledi ◽  
I Parker ◽  
R M Woodward
Keyword(s):  
Xenopus Oocytes ◽  
Divalent Cations ◽  
Membrane Currents

scholarly journals Chloride-ion concentration dependence of molecular dimension in the acid-denatured state of equine β-lactoglobulin

2007 ◽  
Vol 40 (s1) ◽  
pp. s213-s216 ◽  
Author(s):  
Yoshiteru Yamada ◽  
Takeo Yajima ◽  
Seiichi Tsukamoto ◽  
Kanako Nakagawa ◽  
Kazuo Fujiwara ◽  
...  
Keyword(s):  
Concentration Dependence ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Denatured State ◽  
Molecular Dimension ◽  
Β Lactoglobulin
Sign in / Sign up

Export Citation Format

Share Document