Novel concentration effect in an ities study of facilitated potassium ion transport

To examine the relationships between brain glycolysis, ion transport, and mitochondrial reduction/oxidation (redox) activity, extracellular potassium ion activity (K+0) and redox shifts of cytochrome oxidase (cytochrome a,a3) were recorded previous to and during superfusion of rat cerebral cortex with the glycolytic inhibitor iodoacetic acid (IAA). IAA produced oxidation of cytochrome a,a3, increased local oxygenation, increased K+0, and, in response to neuronal activation, slowed rates of K+0 reaccumulation. Rates of rereduction of cytochrome a,a3, after the oxidation of this cytochrome by stimulation, were also slowed by IAA. These effects of IAA demonstrate the dependence of K+0 reaccumulation on the integrity of glycolysis, support the concept that active processes are involved in brain ion transport, and suggest a link between ATP supplied by glycolysis and ion transport activity. These data are also compatible with the suggestion that residual dysfunctions after brain ischemia result from derangements in glycolytic functioning rather than from limitations in oxygen availability or oxidative metabolic activity.

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Energetics of Potassium Ion Transport in Aplysia Gut

ZOOLOGICAL SCIENCE ◽

10.2108/zsj.19.629 ◽

2002 ◽

Vol 19 (6) ◽

pp. 629-632 ◽

Cited By ~ 1

Author(s):

George A. Gerencser ◽

Stanley Y. Loo ◽

Kuuleialoha M. Cornette ◽

Jianliang Zhang

Keyword(s):

Ion Transport ◽

Potassium Ion ◽

Potassium Ion Transport

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First-principles molecular dynamics study on ultrafast potassium ion transport in silicon anode

Journal of Power Sources ◽

10.1016/j.jpowsour.2019.01.062 ◽

2019 ◽

Vol 415 ◽

pp. 119-125 ◽

Cited By ~ 11

Author(s):

Sangjin Lee ◽

Sung Chul Jung ◽

Young-Kyu Han

Keyword(s):

Molecular Dynamics ◽

Ion Transport ◽

First Principles ◽

Potassium Ion ◽

Silicon Anode ◽

Potassium Ion Transport ◽

First Principles Molecular Dynamics

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Potassium ion transport by gramicidin and valinomycin across a Ag(111)-supported tethered bilayer lipid membrane

Electrochimica Acta ◽

10.1016/j.electacta.2008.04.043 ◽

2008 ◽

Vol 53 (22) ◽

pp. 6372-6379 ◽

Cited By ~ 28

Author(s):

Lucia Becucci ◽

Massimo Innocenti ◽

Emanuele Salvietti ◽

Alessio Rindi ◽

Irene Pasquini ◽

...

Keyword(s):

Ion Transport ◽

Lipid Membrane ◽

Bilayer Lipid Membrane ◽

Potassium Ion ◽

Bilayer Lipid ◽

Potassium Ion Transport

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Active Potassium Ion Transport Across the Caterpillar Midgut: I. Tissue Electrical Properties and Potassium Ion Transport Inhibition

Journal of Experimental Biology ◽

10.1242/jeb.108.1.273 ◽

1984 ◽

Vol 108 (1) ◽

pp. 273-291

Author(s):

M. V. THOMAS ◽

T. E. MAY

Keyword(s):

Electrical Properties ◽

Ion Transport ◽

Active Transport ◽

Transport System ◽

Reversal Potential ◽

Potassium Ion ◽

Transport Pathway ◽

Tin Chloride ◽

Potassium Ion Transport ◽

Active Transport System

Active potassium ion transport by isolated midguts of Spodoptera littoralis and Manduca sexta caterpillars has been studied by electrical means. In contrast to previous studies, the electrical properties of the midguts remained essentially constant for several hours; this improvement probably results from use of an experimental saline that more closely resembles caterpillar haemolymph. The active transport could be abolished by anoxia and by a number of chemical agents, of which trimethyl tin chloride (effective at 10−9M) was the most potent. Some of these substances, including trimethyl tin chloride, may have been acting directly on the potassium ion transport system. The results of varying the ionic composition of the saline suggest that potassium is the only cation that can be transported at a significant rate. However, the rate of potassium ion transport is increased by the simultaneous presence of other inorganic cations. Experiments to determine the ‘reversal potential’ for the active transport pathway, by varying the potassium ion concentration, suggested that this parameter was not a constant, and thus the active transport system could not be modelled by a simple equivalent electrical circuit, although the midgut epithelium is not unique in this respect. Therefore, the tissue electrical properties could not readily be correlated with the energetics of the potassium transport process, but the results are nevertheless consistent with a potassium ion: ATP ratio of greater than one, if ATP is indeed the primary energy source.

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