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While this is off the topic of CRON, it's an interesting report on

other life extension research being done at UC .

---------------------------------

Science News

Week of June 14, 2003; Vol. 163, No. 24

Lease on Life: Old mice live longer when given young ovaries

Sorcha McDonagh

Here's one more reason to be obsessed with reproduction. A new study

with aging mice suggests that the reproductive system plays a role in

determining how long animals live.

Carey and his colleagues at the University of California,

transplanted ovaries from 2-month-old mice into mice whose ovaries

had been removed a few weeks after birth. The procedure extended some

of the animals' lives. It proved equivalent to enabling a 50-year-old

woman to live to age 92 instead of 80, her current life expectancy,

Carey explains.

" The gonads are communicating with the body to stay young for

reproduction, " he says.

In the June Aging Cell, Carey and his coworkers describe their

experiments with five groups of female mice. One group retained its

original ovaries. In four groups, the researchers removed the

animals' ovaries when the mice were only 3 weeks old and thumbnail

size. Of those mice, one group remained without ovaries. The

researchers transplanted 2-month-old ovaries into the other groups

when the animals reached 5, 8, or 11 months of age.

Carey compared the remaining life expectancies of each group when the

mice were 11 months old, an age at which they're normally no longer

capable of reproduction. The mouse group that had their original

ovaries had about a month more to live than the group that had their

ovaries removed and not replaced.

A mouse's age when it received its ovary transplant influenced its

life expectancy. The mice that received new ovaries at 11 months of

age benefited most, living 60 percent longer than those that had

their ovaries removed but not replaced and 40 percent longer than

those still with their original ovaries.

The mice that had received ovaries at 8 months had 24 percent longer

to live than the mice with no ovaries did, and the group that

received ovaries at 5 months lived about 7 percent longer.

" Clearly, there's some kind of cross talk between the reproductive

organs and the soma [body] of the animal, " says Leonard Guarente of

the Massachusetts Institute of Technology, who investigates the

genetic factors of longevity.

The ovary-transplant process kills many mouse egg cells. So, it's not

clear whether the differences seen in the experiment result directly

from the transplanted ovaries or indirectly from the reduction in

eggs. In previous research, the nematode Caenorhabditis elegans lived

60 percent longer than normal if its germ cells—eggs or sperm—were

destroyed, Kenyon of the University of California, San

Francisco reported in the Jan. 18, 2002 Science.

Kenyon cautions that the germ-cell connection to longevity she found

in nematodes may not apply to mice. " When we understand both systems

better, " she says, " we can find out whether it's a coincidence or

whether there's some evolutionarily conserved mechanism operating in

the two animals. "

In time, Carey speculates, the research could lead to life-prolonging

interventions that exploit whatever signal helps keep the mice

youthful.

" Reproduction is the cardinal function in life, " Carey says. " It

denies logic to believe that it isn't central to aging. "

****************

If you have a comment on this article that you would like considered

for publication in Science News, send it to editors@....

Please include your name and location.

References and Sources

References:

Cargill, S., J.R. Carey, et al. 2003. Age of ovary determines

remaining life expectancy in old ovariectomized mice. Aging Cell

2(June):185-190. Abstract available at

http://dx.doi.org/10.1046/j.1474-9728.2003.00049.x

Arantes-Oliveira, N. . . . and C. Kenyon. 2002. Regulation of

life-span by germ-line stem cells in Caenorhabditis elegans. Science

295(Jan. 18):502-505. Abstract available at

http://www.sciencemag.org/cgi/content/abstract/295/5554/502.

Further Readings:

Hsin, H., and C. Kenyon. 1999. Signals from the reproductive system

regulate the lifespan of C. elegans. Nature 399(May 27):362-366.

Abstract available at http://dx.doi.org/10.1038/20694.

Sources:

R. Carey

Department of Entomology

University of California,

1 Shields Avenue

, CA 95616-8584

Lenny Guarente

Department of Biology

Massachusetts Institute of Technology

31 Ames Street, Room 68-132

Cambridge, MA 02139

Kenyon

Department of Biophysics and Biochemistry

University of California, San Francisco

600 16th Street, Room S314

Box 2200

San Francisco, CA 94143-2200

http://www.sciencenews.org/20030614/fob4.asp

From Science News, Vol. 163, No. 24, June 14, 2003, p. 372.

Copyright © 2003 Science Service. All rights reserved.

---------------------------------

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subscribing to Science News. Visit Science News Online at

http://www.sciencenews.org/ for access to additional news articles and

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