Talk:Na+/K+-ATPase

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Pharmacology[edit]

Could someone please rework the pharmacology section so that the role of Na/K ATPase in Ca2+ sequestration is more clear?

Nomenclature[edit]

Is sodium pump not a more generally used name??

You could add mention of sodium pump to the article. It gets 1886 hits on this search engine. There should probably be an entire section of the article that describes the various versions of the name. They list six here. —Preceding unsigned comment added by 84.51.156.172 (talkcontribs) . Signed by Brazucs
Please add ~~~~~ to the end of your comments on discussion pages. --JWSchmidt 13:20, 14 December 2005 (UTC)
I have always seen it written as sodium-potassium pump. --Brazucs (TALK | CONTRIBS) 05:08, 19 April 2006 (UTC)
there are a class of sodium-specific channels essential for membrane depolarization, and the pump/channel could be confusing. Sovbeos 14:05, 25 September 2007 (UTC)

Name[edit]

I find the plus signs in the title of this article distracting. I propose we instead use the much cleaner "Na,K-ATPase", which is used in several physiology textbooks, notably Boron and Boulpaep's Medical Physiology. Thoughts? --David Iberri (talk) 21:47, 20 May 2006 (UTC)

I agree Sovbeos 14:05, 25 September 2007 (UTC)

Nursing Implications of Sodium Potassium Pump[edit]

Requesting fluid and electrolyte, and IV implications of the sodium potassium pump mechanism. This seems like a lot of information with no practical application, and is therefore difficult to conceptualize. 76.19.146.152 23:36, 6 March 2007 (UTC)ASB

Working in reverse?[edit]

According to my Cellular Biology textbook (ISBN 0815332181) the sodium-potassium ATPase can also work in reverse. Under a high K+/Na+ electro-chemical gradient and depending on the concentrations of ADP and ATP inside the cell, the enzyme can phosphorylize ADP by transporting Na+ into the cell and K+ out of the cell. Seems to be an equilibrium sort of thing. If anyone can confirm, please add it to the article. Aurimas 05:26, 19 September 2007 (UTC)


It can work in reverse, since it basically is a chemical reaction. However, under normal circumstances, it does not do so. 2001:610:1908:C000:C1A7:8F9:D8B9:45BD (talk) 12:00, 13 July 2012 (UTC)

Remove exclamation mark in "Function - Mechanism"[edit]

It's a serious article, and the fact that the reaction repeats itself again does not mean it is funny, or requires an exclamation mark —Preceding unsigned comment added by 194.81.255.254 (talk) 17:17, 14 October 2007 (UTC)

Why an enzyme[edit]

The definition that I have always been told, which now seems to be wrong, is that an enzyme is biological catalyst, speeding up reactions, is this definition incomplete because this doesn't seem to be changing a reaction speed. —Preceding unsigned comment added by Murdochious (talkcontribs) 21:27, 5 November 2007 (UTC)

I noticed that too, in Neuroscience (Purves et. al. 2007) on p 77 it describe active transporters (of which, the sodium potassium pump is one) as plasma membrane proteins. Paskari (talk) 14:55, 1 September 2008 (UTC)

From a chemical point of view, the Na,K-ATPase catalyses the reaction in which ATP becomes ADP. (It moves Na and K in the process.) Therefore it is technically an enzyme. 2001:610:1908:C000:C1A7:8F9:D8B9:45BD (talk) 12:14, 13 July 2012 (UTC)

Critisism to Na+/K+-ATPase[edit]

I added a section about the critisism of the Na+/K+-ATPase. It was reverted by User:JWSchmidt http://en.wikipedia.org/w/index.php?title=Na%2B/K%2B-ATPase&oldid=184179079 I admit that I don't have the capability to see if it's a fringe website, but it seems to me that it should be mentioned in the article, because this specific theory has been widespread in the media (UTFG); even more then if someone here could provide a link which gives a counterview to the theories of Gilbert Ling, which may eventually expose them as a fringe science. --84.226.130.70 (talk) 03:58, 14 January 2008 (UTC)

Please suggest one or more specific peer-reviewed publications which gives a critical view of the Na+/K+-ATPase.....we can start from there. A personal website is not a good source to cite. --JWSchmidt (talk) 04:07, 14 January 2008 (UTC)
That's true indeed. I took a look at the 3 disprovals which Ling lists on his website [1]. (1) is a overview of different research papers (done by Ling himself) published by Blaisdell Pub. Co (2) is an article by Mullins and Brinley published in The Journal of General Physiology (3) is an article (again by Ling himself) published in The Journal of Physiology. Again I have to admit that I'm not familiar with this specific scientific community. I assume that (2) and (3) were peer reviewed, while (3) is more likely to criticise the Na+/K+-ATPase as it is from Ling himself. However the abstract of (3) does not itself directly mentions a disproval. --84.226.130.70 (talk) 05:57, 14 January 2008 (UTC)
In (3), Ling seems particularly concerned with promoting the idea that in living cells, "anionic sites of certain protoplasmic proteins.....have more favourable adsorption energies for K+ than for Na+." He proposed that this selectivity for K+ binding to cellular proteins depends on ATP. "When ATP is removed during cell deterioration, the system goes into an alternative co-operative state, in which selectivity for K+ adsorption is lost". There is a rather extensive literature on ATP-binding proteins...are there any good publications that describe proteins shifting their K+-binding affinity in an ATP-depedent way? --JWSchmidt (talk) 22:59, 14 January 2008 (UTC)

In light of the following information (a Nobel Prize winner in Physics being fascinated by Ling's A-I Hypothesis), I think it would be reasonable to put the "The Critisism to Na+/K+-ATPase" back into the main article. Wikipedia should not hinder anyone to pursue knowledge.

Yang received the Nobel Prize in Physics in 1957 and is considered one of the worlds foremonst authorities on cooperative phenomena. He was fascinated by Ling’s A-I Hypothesis, which was accessible to him through his own work with the Ising model of magnetism. The Ising model forms the basis of modern physics theory of phase transitions (the familiar examples are condensation of steam into water and the freezing of water into ice) and, more generally, of cooperative phenomena. Yang — currently the Einstein Professor of Physics and Director of the Institute of Theoretical Physics of the State University of New York at Stony Brook — worked with Ling to further develop one aspect of the A-I Hypothesis, the idea of near neighbor interaction (cooperativity). Together, they applied the one dimensional Ising model to the biological polymer and, as Ling said, “We have been using that to describe quantitatively the behavior of in vitro (in glass) and in vivo (living) systems with considerable success.” (http://gerson-research.org/docs/HildenbrandGLG-1979-1/index.html) —Preceding unsigned comment added by 84.114.147.43 (talk) 13:10, 21 August 2010 (UTC)

Gerald H. Pollack, Professor of Bioengineering at the University of Washington, writes in his 2001 book "Cells, Gels and The Engines of Life": "I warmly acknowledge the influence of Gilbert Ling. [...] It became clear that an approach to cell physiology orthogonal to current wisdom had considerable merit and enjoyed appreciable experimental support from a cadre of intellectually independent scientists. Ling has been a continuing force [...] for myself. Without his influence, this work would never have begun."

Another paper: http://www.ncbi.nlm.nih.gov/pubmed/16359622 "Doubts about the sodium-potassium pump are not permissible in modern bioscience." (... or wikipedia, for that matter.) —Preceding unsigned comment added by 91.115.46.206 (talk) 17:13, 24 April 2011 (UTC)

Gilbert Ling's Association-Induction Hypothesis definitely warrants some consideration. He has conducted an experiment in the 50s where he deactivated all the energy systems of a cell, especially ATP, by poisoning them. Remarkably, the cells maintained a high amount of potassium compared to the external solution, despite not using ATP to power sodium pumps as expected by the Sodium Pump Theory. The Sodium Pump Theory demands vast amounts of energy not available in the experiment, yet the cell managed to maintain its potassium levels, despite the flow of Sodium and Potassium ions throughthe membrane. I'm not very scientifically literate, but the Association-Induction Theory at least deserves mention in an article about the Sodium Pump theory.

Gilbert Ling's theory states that water molecules are more structured than most people think. Water molecules inside a cell are not free liquid water, and they can and are organized around protein and lipid compounds. The interior of a cell is inconceivably complex and complicated. Indeed, NMR spectroscopy discovered that water molecules tend to be more organized, almost crystalline, the closer they are to the structures of a cell.

Gilbert Ling and his followers have been made pariahs in the supposedly open and unbiased scientific community for merely challenging what had been fervently believed in, yet not fully explained, by the academia. He and his colleagues have repeatedly asked for opportunities to debate the two theories, but they have been denied this opportunity. The overwhelming negative response to this theory has caused many scientists to avoid speaking about it openly for the sake of keeping their careers. Gilbert Ling himself was a successful scientist until he supported bulk phase theories.

Again, I'm not very well-versed in all this, but it seems that there should be at least some discussion here. — Preceding unsigned comment added by 69.107.85.51 (talk) 06:12, 3 July 2011 (UTC)

Controlling of cell volume[edit]

The last few sentences could be cleared up a little bit:

  • The pump transports 3 Na+ ions out of the cell and in exchange takes 2 K+ ions into the cell... This represents a continual net loss of ions out of the cell. As a result an opposing osmotic tendency operates to drive the water molecules out of the cells.

This makes it seem like the cell is going to shrivel up and die. I'm assuming all this does is counteract the influx of water molecules, correct? Furthermore, why does removing 3 sodium ions and inserting 2 potassium ions force water molecules out of the cell? Paskari (talk) 15:02, 1 September 2008 (UTC)

The old part is very vague but also wrong. The whole story is quite involved. I will take out the biggest part. I put some explanation here, but I think it is too involved for this article and I have no proper reference. Cell swelling is due to a higher concentration of particles in the water inside the cell than outside (see osmosis). The effect on the cell swelling cannot be explained by considering osmosis with only Na+ and K+ ions (or any other ion with +1 unit charge). At the resting voltage potential, a pump is pumping 2 K+ ions into the cell, and pumps 3 Na+ ions out of the cell. Since this is a nett electrical current, it makes the cell's membrane voltage slightly more negative. This causes a passive influx of 1 K+ ion, driven by the membrane voltage. Resulting in no nett current and no nett osmolality (particle density) change. If there would be no other ions, stopping the pumps causes an equal influx of Na and efflux of K. (Almost equal. Actually, a very small difference causes the depolarization of the membrane.) This does not result in any change in osmolality. What does change the osmolality, is an influx of negatively charged ions (i.e. Cl-) (together with positive ones so there's no nett current). When the membrane potential would be less negative, more Cl- ions would flow into the cell resulting in cell swelling. Therefore, the NaK-pump does prevent cell swelling. 128.127.38.168 (talk) 20:47, 13 July 2012 (UTC)

Nam Currie-Nyugen[edit]

The article lists Nam Currie-Nyugen as the discoverer of a fundamental process in this article but I cannot find reference to it anywhere. Can someone please confirm this or remove the reference? Thanks Oniamien (talk) 03:36, 16 September 2008 (UTC)

Resting potential[edit]

There appears to be some confusion in this section. Action potentials do not, in fact, alter the relative concentrations of Na and K ion very much, and excitable cells can fire action potentials for some time after active transport is inhibited (for a good reference, see Hille (2001) Ionwoo!!!!!!!!! channels of excitable membranes). The mention of the hyperpolarisation is irrelevant in this section also, and adds to the confusion. The basic point that needs to be made is that active transport establishes and maintains a concentration gradient in the face of ongoing activity and passive leak.

---01/19/2011 I feel this description of the AP is out of place and should be removed entirely. The Na/K pump has little to do with it. Moreover, if someone does not already understand this, I believe they might find this section to be very confusing. --- —Preceding unsigned comment added by 130.64.41.44 (talk) 20:54, 19 January 2011 (UTC)

Nitrophenol[edit]

It's function as a metabolic inhibitor of the pump ought to be mentioned —Preceding unsigned comment added by 99.255.162.25 (talk) 19:33, 17 April 2009 (UTC)

"in all animals". No Na/K pump in plants/microbes?[edit]

Just found that line a bit confusing, surely it exists in some plants and microbes? --Hellofraance (talk) 22:12, 23 January 2010 (UTC)

It may, but I don't think it MUST, since many of these don't need sodium at all for life (some plants do and some don't). So what use a sodium pump if you don't need sodium? SBHarris 03:06, 24 January 2010 (UTC)

In this same vein, I came here looking to see if the pump was present in all animal cells or just in neurons. I think that would be helpful information at the beginning of the article. (I found the answer in a textbook; yes, all animal cells have these things) —Preceding unsigned comment added by 137.82.82.141 (talk) 03:00, 1 April 2011 (UTC)

Function[edit]

Energy expenditure[edit]

The opening paragraphs repeat the text book stance that "the Na+/K+-ATPase consumes about 1/3 of the cellular energy". In Pollard & Earnshaw, Cell Biology, 2nd ed, 2008 Saunders-Elsevier, Philadelphia (p134) they quote "...consuming up to 25% of total cellular ATP" without citing sources.

In the review D. F. Rolfe and G. C. Brown. Cellular energy utilization and molecular origin of standard metabolic rate in mammals. Physiol Rev, 77(3):731–58, Jul 1997, PMID: 9234964 [2] I found

"The Na+/K+-ATPase is an important ATP consumer although its importance may have been overestimated previously [...] The estimated coupling to oxygen consumption of the Na+/K+-ATPase is [...] about 20% in humans [...] The contribution is particularly large in brain and kidney where the pump has been estimated to be coupled to 50–60% of oxygen consumption."

Given that oxygen consumption is generally used as a measure of ATP production, I would suggest to modify the sentence to

For most animal cells, the Na+/K+-ATPase is responsible for about 1/5 of the cell's energy expenditure [1]

(change "1/3" to "about 1/5" + citation, of course remove my bold-highlighting). — Lomenoldur (talk) 02:03, 15 August 2012 (UTC)

No-one seems to object so I am changing it in the article. Note that Citizendium:Na,K-ATPase actually got it pretty much right (I only saw that one later). — Lomenoldur (talk) 20:06, 17 August 2012 (UTC)
This should be changed further as the given reference says nothing about "cells" but instead references a second review article:
T Clausen, C Van Hardeveld,and M E Everts
Significance of cation transport in control of energy metabolism and thermogenesis.
Physiol Rev July 1991 71:733-74
This review article only makes a statement regarding total basal metabolic rate:
"In view of these uncertainties, a quantitative estimate of the Na+-K+ pump-dependent fraction of basal metabolic rate in the intact organism has to be based on measurements performed on representative tissues or cells. If it is assumed that each of them contributes to the basal metabolic rate by the fractions generally reported (146) and given in Table 4, then it can be calculated that the sum of the Na+-K+ pump-dependent O2 consumption corresponds to ~20% of the total basal metabolic rate."
Where reference 146 is a textbook from 1971:
Circulation / [by] Björn Folkow [and] Eric Neil.
Folkow, Björn
New York : Oxford University Press, 1971.
Given that the review articles do not state what is claimed here, this textbook is over 40 years old, not easy to find, and is most likely not the original source of the data itself even after following two other references, I am going to replace the reference with citation needed. There must be more recent, reliable literature on this topic.207.229.179.97 (talk) 19:32, 9 January 2013 (UTC)

References[edit]

  1. ^ Rolfe, D. F.; Brown, G. C. (1997). "Cellular energy utilization and molecular origin of standard metabolic rate in mammals". Physiological reviews 77 (3): 731–758. PMID 9234964.  edit