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[A1CR]

[posted on behalf of CRON4healthyfuture; 2003-07-12]

Gainesville weighs in on MiFRA theory (de Grey gets an F); No effect of Caloric Restriction on ATP production

They took isolated mitochondria, and they couldn't find jack. Are you
going to expect me to believe that the common deletion is having any
meaningful impact organismal physiology if mitochondrial dysfunction cannot
be isolated with such a powerful and innovative experimental technique?

Now I understand that cytochrome b is not affected by the common deletion,
but other mitochondrial proteins are. And yet they can't find anything
here!

So the MiFRA myth goes that a handful of mitos is all you really need, and
that the "big picture" is not important. IF this were the case, I would
think that they would of occasionally "stumbled" across one of these
defective mitochondria, since they were grabbing isolated ones and seeing
if they still get the job done. And they could.

This lab in Gainesville is basically taking Barja's boo-boo and running
with it, and they got another decent publication out of it. This body of
research is going to blow up in the face of MiFRA advocates, and this is
just the beginning.

=-=-=-=-=-=-=-=-=-=-=-=-

"In both tissues, neither age nor caloric restriction had any significant
effect on the ATP content or the rate of ATP production. This study
introduces a highly sensitive, reproducible, and quick methodology for
measuring ATP in isolated mitochondria."

=-=-=-=-=-=-=-=-=-=-=-=-=

Am J Physiol Regul Integr Comp Physiol. 2003 Jul 10 [Epub ahead of print].
Related Articles, Links

Method for measuring ATP production in isolated mitochondria; ATP
production in brain and liver mitochondria of Fischer-344 rats with age and
caloric restriction.

Drew BR, Leeuwenburgh C.

Biochemistry of Aging Laboratory, University of Florida, Gainesville, FL,
USA.

The production of ATP is vital for muscle contraction, chemiosmotic
homeostasis, and normal cellular function. Many studies have measured ATP
content or qualitative changes in ATP production but few have quantified
ATP production in vivo in isolated mitochondria. Because of the importance
of understanding the energy capacity of mitochondria in biology,
physiology, cellular dysfunction and ultimately disease pathologies and
normal aging, we modified a commercially available bioluminescent ATP
determination assay for quantitatively measuring ATP content and rate of
ATP production in isolated mitochondria. The bioluminescence assay is based
on the reaction of ATP with recombinant firefly luciferase and its
substrate luciferin. The stabilities of the reaction mixture as well as
relevant ATP standards were quantified. The luminescent signals of the
reaction mixture and a 0.5 micro M ATP standard decreased linearly at rates
of 2.16% and 1.39% decay/minute, respectively. For a 25 micro M ATP
standard, the luminescent signal underwent a logarithmic decay, due to
intrinsic deviations from the Beer-Lambert Law. Moreover, to test the
functionality of isolated mitochondria, they were incubated with 1 and 5 mM
oligomycin, an inhibitor of oxidative phosphorylation. The rate of ATP
production in the mitochondria declined by 34% and 83%, respectively. Due
to the sensitivity and stability of the assay and methodology, we were able
to quantitatively measure in vivo the effects of age and caloric
restriction on the ATP content and production in isolated mitochondria from
the brain and liver of young and old Fischer-344 rats. In both tissues,
neither age nor caloric restriction had any significant effect on the ATP
content or the rate of ATP production. This study introduces a highly
sensitive, reproducible, and quick methodology for measuring ATP in
isolated mitochondria.

PMID: 12855419 [PubMed - as supplied by publisher]

[MR]

"CRON4healthyfuture" wrote:
> >
> > They took isolated mitochondria, and they couldn't find jack.

*Yawn.*

They took isolated mt, and couldn't find any significant effect of CR on
the ATP content or the rate of ATP production. Since MiFRA does not
posit any hypothesis regarding age-related decline in mtATP production,
or of its reversal by CR or other successful anti-aging interventions
(as you would know perfectly well if you'd read de Grey's book, or paid
any attention to the previous 2 posts wherein I've pointed this out to
you), it's hard to see what (beyond simple ignorance on the subject on
your part) underlies your subject line, or the contents or general tone
of your post.

-MR

> > =-=-=-=-=-=-=-=-=-=-=-=-=
> >
> > Am J Physiol Regul Integr Comp Physiol. 2003 Jul 10 [Epub ahead of print].
> > Related Articles, Links
> >
> > Method for measuring ATP production in isolated mitochondria; ATP
> > production in brain and liver mitochondria of Fischer-344 rats with age and
> > caloric restriction.
> >
> > Drew BR, Leeuwenburgh C.
> >
> >
> > PMID: 12855419 [PubMed - as supplied by publisher]