could extend life expectancy and Slow Aging
August 27th 2005
Researchers at the University of Texas Southwestern Medical Center led
by Dr. Makoto Kuro-o (M.D., Ph.D.) found that a naturally occurring
hormone called Klotho extended the lifespan of mice up to 30%. They
also found that it increases the susceptibility to diabetes and
decreases fertility. The study was reported in the online journal
The hormone is produced in the kidney and brain but can leak into the
bloodstream. It is the leakage that helped the mice live longer, so it
appears. Researchers will be looking into whether people that live
longer have an surplus of this hormone in the blood.
earlier mice study conducted by Dr. Kuro-o in 1997 found that mice that
lacked the hormone had significantly shorter life spans. They found the
mice developed ailments including hardening of the arteries, thinning
bones, withered skin, and weak lungs.
The Texas team identified a small protein component peptide that the so
called Klotho gene produces. They were able to genetically engineer
normal mice by injecting them with this purified peptide. The
genetically engineered male mice lived 31% longer than normal males.
The modified females lived 19% longer.
There does not appear to be any food
or drug that stimulates Klotho secretion. Dr. Kuro-o told Best
Syndication that "At this moment
I do not know that there is anything that can stimulate Klotho
secretion." Cells naturally die off as we age. This is not
the same for cancer cells. Cancer cells do not die but continue to
multiply. This has been a common concern in longevity research.
Dr. Kuro-o told Best Syndication that "We do not observe an
increase in cancer in transgenic mice that overexpress Klotho at this
moment. Effects of Klotho on cancer remains to be determined."
The team noticed the hormone increased the body’s resistance to
insulin. Previous studies have shown this condition correlates to an
extended life span. Ultra-low calorie diets also increase insulin
Experiments involving cells in the laboratory indicated the peptide
substance modulates a crucial biological pathway involving basic
metabolic functions. It is interesting that the mice did not have an
increased level of glucose in their blood which is a primary symptom of
Other studies found that “damping down” this insulin/insulin-like growth
factor-1 signaling pathway may be the same mechanism that extends
longevity in animals that were fed ultra-low calorie diets. Previous
research found that people with a certain variation of the gene are
prone to age related diseases like heart attacks, strokes and
Klotho is named after one of the Greek Goddesses who
thread of life
controlling the longevity of individual humans. It is hoped that this
could lead to drugs that increase human life spans.
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By Dan Wilson
Best Syndication Staff Writer
Books on Aging
Keywords and misspellings: Klotho clotho ageing aging