I posted this on another newsgroup:
This topic came up in discussions because of the claim that PUFAs are
necessary to "keep cell membranes flexible," though there is no
evidence that one must consume either omega 3 or omega 6 PUFAs in order
to accomplish this. Moreover, simple experiments could be done, to see
if the "cell membranes" of rats, for example, "stiffen up" if fed a fat
free diet. As long ago as 1948, such an experiment was done, and the
rats were fine. In any case, if anyone found this topic of interest,
here is some new information:
QUOTE: ...Gerald Pollack is only the messenger as far as what he has
written about the sodium pump is concerned. He actually tells a story
that was originally written by Gilbert Ling. I had to obtain a copy of
one of Gilbert Ling's recent publications (Physiol. Chem. Phys. &
Med. NMR 29: 123-198, 1997) to gain a glimpse of the turmoil that has
existed in the sodium pump field for about 50 years! Gilbert Ling
carried out some simple experiments (simple in terms of what he was
trying to observe: complex in terms of experimental design) as part of
his Ph.D work. His observations did not fit with the then current
understanding of the sodium pump. He writes that he was quietly advised
that the sodium pump was a 'Holy Cow' and that he should stay away
from it. He didn't. His research funding dried up. His research
students fled for fear of becoming unemployable. A smear campaign was
instigated to blacken his name. But his results are clear: if you
poison frog sartorius muscle with sodium iodoacetate, and/or provide a
nitrogen atmosphere and/or cool the muscle preparations down to 0°C,
ATP production should cease and the sodium pump should stop working.
This should result in intracellular sodium levels rising as the sodium
pump fails. But that is not what happens. If you want to see how Gerald
Pollack tells the story, get his book. Suffice it to say that the
sodium pump may well use ATP to do something that results in the
movement of sodium and potassium ions in opposite directions across
membranes, but that something has little if anything to do with
maintaining potassium at high level and sodium at low level
intracellularly. You don't need a sodium pump to achieve this end
because it happens spontaneously! If you are troubled by this
observation, you should get Gerald Pollack's book.
But there is much more to Gerald Pollack's book than a wish to
revisit the sodium pump and to focus, for a change, on the water in
living systems rather than on the proteins, carbohydrates,
phospholipids, salts, etc. He develops a story that eloquently moves
the reader towards a single unifying hypothesis built around phase
transitions that occur in the structured water environment of living
cells. The same phase transition phenomena can, it seems, provide
mechanistic explanations for a multitude of intracellular events that
are currently understood only in terms of the words that describe the
observable phenomena. Consider, for example, what it is that you
actually understand by the phrase 'secretion of a
neurotransmitter'. You could probably describe what is actually
observed during this process, but could you explain mechanistically how
secretion happens? Or how cell division happens? Or how muscle cells
contract? Or how action potentials propagate (yes, I too have read the
undergraduate textbooks, but the story about action potentials as it is
commonly told, like the sodium pump story, contains rather significant
omissions)? Or how transport of substances occurs through the
gelatinous mass that is the intracellular environment (this is, I would
submit, of fundamental significance to our understanding of
intracellular therapeutic targeting of bioactive molecules)? Or how ATP
works (yes, yes, I too have read the undergraduate textbooks and
lectured on the subject)? Gerald Pollack attempts to do all of this and
more. And I have to say that I find the case he makes compelling...
Richard J. Schmidt, J. Pharmacy and Pharmacology 55: 857-858, 2003
UNQUOTE.
QUOTE: In conclusion, the aqueous information transfer within the cell
involves the following:
Intracellular water favours K+ ions over Na+ ions.
Freely rotating proteins create zones of higher density water, which
tend towards a lower density clustering if the rotation is prevented.
Static charge-dense intracellular macromolecular structures prefer K+
ion pairs to freely soluble K+ ions.
Ion paired K+-carboxylate groupings prefer local clathrate water
structuring.
Clathrate water prefers local low density water structuring.
Low density water structuring can reinforce the low-density character
of neighbouring site water structuring.
Na+ and Ca2+ ions can destroy the low density structuring in a
cooperative manner.
Martin Chaplin [author of the above] is Professor of Applied Science,
London South Bank University, UK, with special interests in the
interactions between water and biological molecules. UNQUOTE.
QUOTE: In the course of developing these techniques, Edelmann also
confirmed a major prediction of AIH, that cellular potassium is
adsorbed at negatively charged sites of cellular proteins, and not
freely dissolved in cell water as was generally assumed. This
assumption inevitably led to the major dogma of contemporary cell
biology that Gilbert Ling has thoroughly deconstructed: that a sodium
/potassium pump is responsible for pumping sodium ions (Na+) out of the
cell and potassium ions (K+) into the cell, thereby keeping
intracellular K+ concentration high and Na+ concentration low.
The most spectacular visualization of potassium adsorption was achieved
using a method developed by Ling, which was to reversibly replace
potassium ions of living muscle cells with chemically similar heavy
ions such as caesium or thallium before cyrofixation and freeze-drying.
Electron micrographs of thin sections of this muscle demonstrated
directly the localisation of the electron-dense heavy metal ions at the
myosin protein bands as predicted (see Fig. 2). Edelmann has
demonstrated similar localised methods...
In his search of the protein structure in living cells, Edelmann
obtained images that have never been seen before. The outer membrane of
the cell as well as membranes inside the cell appear in negative
contrast, i.e., bright, as opposed to dark, as is usually seen, while
proteins of subcellular compartments appear very homogeneously
distributed instead of being heterogeneous or fibrous, suggesting that
the latter may be artefacts. UNQUOTE.
Source: http://www.i-sis.org.uk/WITCRL.php
QUOTE: ...where is the cytoskeleton? Using antibody-staining
techniques, Frank Mayer has found evidence of abundant fibrous proteins
that form a web-like structure just inside the inner membrane, to which
the ribosomes - organelles for synthesizing proteins - are
attached. UNQUOTE.
Written by Dr. Mae-Wan Ho. Source: http://www.i-sis.org.uk/WITBRL.php
QUOTE: "It is high time a good book was available to not only teach
biologists some physics, particularly bioenergetics, but make them sit
up and think a bit more deeply about it. This little volume is more
readable than other drier and much weightier books on the subject."
Cell Biology International UNQUOTE.
Source: http://www.i-sis.org.uk/rnbwwrm.php
A commentary on the book, The Rainbow And The Worm: The Physics of
Organisms,
by Mae-Wan Ho |
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