"Disposable Soma" Theory of Aging
iam at CHOLLIAN.DACOM.CO.KR
Thu Jul 25 04:05:29 EST 1996
Hi! Dear Friends who are interested in aging mechanism all around world.
Today, I want to talk about the *disposable soma * theory.
I have though over the connection between aging process and reproduction
for a long time. In virtue of the *diposable soma* theory, I*ve got many
insights into aging process. Many aging researches are focused on the
cellular or molecular level of aging process. I want to see aging
process in the level of organism. In that point, the theories of
evolution of aging are helpful to me.
According to the *disposable soma theory* because of the requirement for
reproduction, natural selection favors a strategy that invests fewer
resources in maintenance of somatic cells and tissues than are necessary
for indefinite survival. This beautiful hypothesis are based on the fact
that both somatic maintenance and reproduction require energy.
This theory predicts that aging is due to the accumulation of unrepaired
somatic defects and the primary genetic control of longevity operates
through selection to raise or lower the investment in basic cellular
maintenance systems in relation to the level of environment hazard.
This theory also proposes that a high level of accuracy is maintained in
immortal germ line cells, or alternatively, that any defective germ
cells are eliminated. More interestingly, some taoists in ancient China
avoided their reproductive activities in order to save energy, in their
terms, 'Ki', turning it into making their body young as long as
I have several questions on the *disposable soma * theory
1. If this theory is true, early castrated animals must live more
longer period than do non-castrated animals because early castration
abolishes the energy demands for reproduction, turning some extra-
energy back into the use for the body maintenance. I think it is the
most simplest way to test this hypothesis.
Is there any evidence to support the early castration effect on
life extension in animals or even in humans?
2. How much energy do the gametogenesis require over the entire life
of that organism? How does reproductive demands for energy compete
with that of body maintenance and repair?
In other words, for what life resources is such a competition made?
3. Is there any aging control gene that might be a coordinate
regulator of a range of stress response genes that shift cellular
physiology toward maintenance? In a recent issue .of Science,
Gordon J. Lithgow et al. suggest that age-1 may be such a candidate
because age-1 mutant strains of C. elegans are better equipped than
their wild type counterparts to overcome the effects of extrinsic
stress, such as better resistance to oxidative stress and fewer
deletions of the mitochodrial genomes.
I am thinking over the epigenetic control of such a gene to stop
aging process. I am eager to know what signals or factors in blood
can activate longevity assuring pathways in metabolism.
4. Is it true that higher accuracy is maintained in immortal germ
line cells than do somatic cells?
5. Is there any evidence or opinion that sex hormones have some effects
on aging process?
I am looking forward to people who are very kind enough
to answer my questions :)
Thanks for reading my post.
Hangjun Chang M.D.
iam at chollian.dacom.co.kr
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