belgareth
09-27-2006, 01:29 PM
Too much testosterone kills brain cells By Maggie Fox, Health and Science
Correspondent
Wed Sep 27, 8:23 AM
ET
WASHINGTON (Reuters)
- Too much testosterone can kill brain cells, researchers said on Tuesday in a finding that may help explain why
steroid abuse can cause behavior changes like aggressiveness and suicidal tendencies.
Tests on brain cells in lab dishes showed that while a little of the
male hormone is good, too much of it causes cells to self-destruct in a process similar to that seen in brain
illnesses such as Alzheimer's.
"Too little testosterone is bad, too
much is bad but the right amount is perfect," said Barbara Ehrlich of Yale University in Connecticut, who led the
study.
Testosterone is key to the development, differentiation and
growth of cells and is produced by both men and women, although men produce about 20 times more of the
hormone.
It can also be abused, and recent scandals have involved
athletes who use the hormone, or steroids that turn into testosterone in the body, for an unfair
advantage.
"Other people have shown that high levels of steroid can
cause behavioral changes," Ehrlich said in a telephone interview.
"We
can show that when you have high levels of steroids, you have high testosterone and that can destroy the nerve
cells. We know that when you lose brain cells you lose function."
Ehrlich's team tried the same thing with the "female" hormone estrogen, just to be
fair.
"We were surprised, but it actually looks like estrogen is
neuroprotective. If anything, there is less cell death in the presence of estrogen," she
said.
Writing in the Journal of Biological Chemistry, Ehrlich and
colleagues said their findings meant people should think twice about supplementing with testosterone, even if it
does build muscle mass and aid recovery after exercise.
"These effects
of testosterone on neurons will have long term effects on brain function," they
wrote.
"Next time a muscle-bound guy in a sports car cuts you off on
the highway, don't get mad -- just take a deep breath and realize that it might not be his fault," Ehrlich said in
a statement.
The cells die via a process called apoptosis, also known
as cell suicide or programmed cell death.
"Apoptosis is an important
thing for the brain -- the brain needs to weed out some of the cells. But when it happens too frequently, you lose
too many cells and causes problems."
A similar process is seen in
Alzheimer's disease, the most common cause of dementia in the United States, affecting an estimated 4.5 million
Americans, and Huntington's disease, another fatal brain illness.
"Our
results suggest that the responses to elevated testosterone can be compared with these pathophysiological
conditions," the researchers wrote.
Correspondent
Wed Sep 27, 8:23 AM
ET
WASHINGTON (Reuters)
- Too much testosterone can kill brain cells, researchers said on Tuesday in a finding that may help explain why
steroid abuse can cause behavior changes like aggressiveness and suicidal tendencies.
Tests on brain cells in lab dishes showed that while a little of the
male hormone is good, too much of it causes cells to self-destruct in a process similar to that seen in brain
illnesses such as Alzheimer's.
"Too little testosterone is bad, too
much is bad but the right amount is perfect," said Barbara Ehrlich of Yale University in Connecticut, who led the
study.
Testosterone is key to the development, differentiation and
growth of cells and is produced by both men and women, although men produce about 20 times more of the
hormone.
It can also be abused, and recent scandals have involved
athletes who use the hormone, or steroids that turn into testosterone in the body, for an unfair
advantage.
"Other people have shown that high levels of steroid can
cause behavioral changes," Ehrlich said in a telephone interview.
"We
can show that when you have high levels of steroids, you have high testosterone and that can destroy the nerve
cells. We know that when you lose brain cells you lose function."
Ehrlich's team tried the same thing with the "female" hormone estrogen, just to be
fair.
"We were surprised, but it actually looks like estrogen is
neuroprotective. If anything, there is less cell death in the presence of estrogen," she
said.
Writing in the Journal of Biological Chemistry, Ehrlich and
colleagues said their findings meant people should think twice about supplementing with testosterone, even if it
does build muscle mass and aid recovery after exercise.
"These effects
of testosterone on neurons will have long term effects on brain function," they
wrote.
"Next time a muscle-bound guy in a sports car cuts you off on
the highway, don't get mad -- just take a deep breath and realize that it might not be his fault," Ehrlich said in
a statement.
The cells die via a process called apoptosis, also known
as cell suicide or programmed cell death.
"Apoptosis is an important
thing for the brain -- the brain needs to weed out some of the cells. But when it happens too frequently, you lose
too many cells and causes problems."
A similar process is seen in
Alzheimer's disease, the most common cause of dementia in the United States, affecting an estimated 4.5 million
Americans, and Huntington's disease, another fatal brain illness.
"Our
results suggest that the responses to elevated testosterone can be compared with these pathophysiological
conditions," the researchers wrote.