From: CZJ@CU.NIH.GOV
Newsgroups: bionet.molbio.ageing
Subject: Re:  Chelation therapy and iron [was Re:  Have you heard of
          this?????]
Date: 8 Oct 92 20:44:48 GMT
Distribution: bionet

> In article <1992Oct5.170349.19325@spdcc.com> dyer@spdcc.com (Steve Dyer) writes:
> >In article <1992Oct5.121701.392@lrc.edu> dorham_r@lrc.edu writes:
> >>I would like to know if anyone has heard of chelation therapy.  If
> >>anyone has, could you tell me something about it?  Thanks!!!!
> >
> >Well, there are two kinds of "chelation therapy": are you interested in
> >the bozoid one that people push to "treat" heart disease, or the legitimate
> >therapy used to remove heavy metals like lead and mercury from the body in
> >cases of poisoning?
> >
>
> As Steve points out chelation therapy has a very important and valid use
> in the removal of heavy metals from the body.  An interesting thought given
> the recent study involving the linkage between iron and heart disease
> is whether the mechanism of action of EDTA in improving people with
> heart conditions might be by binding to and removing iron from the
> body.  EDTA is known to bind iron and is commonly used for that
> purpose in free radical experiments.  If it can cause the excretion
> of iron (as it does with lead/mercury) then it would have the same
> effect as donating blood in lowering ones iron stores.
>
> Iron has for a number of years been suspected of playing a key role in
> free radical generation.  [For the chemists, mitochondrial respiration
> generates superoxide which is converted by superoxide dismutase to hydrogen
> peroxide (H2O2).  B-oxidation of fatty acids in the peroxisomes also generates
> H2O2.  Some fraction of the H2O2 escapes the enzymes catalase and glutathione
> peroxidase is converted into hydroxyl radicals which can attack (and oxidize)
> DNA, lipids and proteins in a reaction which requires Fe++ or Cu+ ions.]
> Since our levels of Fe are much higher than our levels of Cu it is a favorite
> choice for involvement in damage to molecules.
>
> There is a great deal of evidence that oxidized cholesterol is consumed
> by macrophages in the process of plaque generation.  If the iron-heart
> disease link is confirmed then iron would be strongly implicated in
> the generation of oxidized cholesterol.  If EDTA can reduce iron levels
> then it may also reduce oxidized cholesterol levels.  This will then
> allow gradual cleanup and widening of the arteries to occur as has been
> demonstrated in Dean Ornish's work with very low-fat diets.
>
> Of course this would be relatively easy to test by measuring iron/ferritin/
> transferrin levels of people who undergo chelation therapy.  If they drop
> significantly after therapy it would be some fairly strong evidence for
> the iron-heart disease link as well as interesting support for such therapy
> in heart disease treatment.  Of course one might be able to obtain the
> same effects by frequently donating blood.  There is a great epidemiological
> study waiting for someone to correlate regular blood donation with heart
> disease/cancer rates.
>
> Robert Bradbury                uunet!sftwks!bradbury or rbradbur@u.washington.edu
>
>

It is been a while since I looked at the literature regarding
chelation therapy but there used to be a lot of discussion
about the problem of iron overload and the use of chelation
therapy to treat it.

The problem is that people who depend on transfusions, for example in
the case of sickle cell anemia and beta thalasemmia build
up iron because the body has no way of excreting it.  The problem
with EDTA was that is was non-specific.  That is sufficient quantities
to remove iron also chelated things like calcium and magnesium.
A fairly specific iron chelator was tried in those days--desferioxamine--
with variable results.

Jim Cassatt