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Diet Drugs May Affect Brain Development

By Julie Steenhuysen,
Reuters
Posted: 2008-05-08 16:10:59
CHICAGO (May 7) - A drug from a new class of weight-loss treatments disrupted wiring needed for brain development in young mice, U.S. researchers said on Wednesday, raising concerns about using such medications in children.

Mark Bear and colleagues at the Massachusetts Institute of Technology studied the effects of a chemical that suppresses appetite by blocking cannabinoid receptors in the brain, the same brain mechanisms that make people hungry when they smoke marijuana.

Scientists from the Massachusetts Institute of Technology found that a chemical analog or copy of Sanofi-Aventis' weight-loss pill rimonabant disrupted wiring needed for brain development in young mice.
Curtis Boles, Oak Ridge National Lab / AP

Scientists from the Massachusetts Institute of Technology found that a chemical analog or copy of Sanofi-Aventis' weight-loss pill rimonabant disrupted wiring needed for brain development in young mice.

"I think that the cautionary note is that these mechanisms play an important role in ... brain development," said Bear, whose study appears in the journal Neuron.

Sanofi-Aventis' weight-loss pill rimonabant, also known as Zimulti and sold under the brand name Acomplia in Europe, is the first in this new class of drugs. A U.S. expert panel rejected it last June because of fears it might trigger suicidal thoughts.

Other drugmakers, including Merck & Co Inc, are working on similar drugs.

Bear's team at MIT was hoping to gain insight into how the brain adapts and rewires itself through learned experiences. This so-called plasticity is central to the development of neurons in the brain of children and young animals.

Bear said these cannabinoid receptors are known to regulate signals between neurons, and his team wanted to see if they would have an effect on plasticity in these young mice.

They were specifically testing learning in the visual cortex of the mouse, a part of the brain that processes information gathered from what they see.

ADAPTING TO CHANGE

Their experiments tested how well the animals adapted if one eye was closed.

The researchers did not use rimonabant in the study. Instead, they used a chemical analog or copy -- in this case a drug available for laboratory use known as AM 251.

When they gave the mice AM 251 to block their cannabinoid receptors, the animals still behaved as if both eyes were open. This suggested the visual cortex was not adapting as it should.

"Our finding of a profound disruption of cortical plasticity in juvenile mice treated with AM 251 suggests caution is advised in the use of such compounds in children," the researchers wrote.

Bear said the finding is similar to the situation with many drugs.

"You have to weigh the benefits against the risks. If the benefit is related more to vanity than morbidity, I don't think the risks are tolerable," he said.

Sanofi-Aventis spokeswoman Julissa Viana said rimonabant is not approved for use in children.

"At this point in time it is approved for use in adults who are overweight and obese with cardiovascular risk factors," she said. "We don't encourage its use in children and it has not been studied nor is it indicated for use in children."

The finding is the latest blow for rimonabant, which once was predicted to be a multibillion-dollar seller.

A study last month of the drug in obese heart patients found more than 40 percent of patients who took the drug developed psychiatric problems.

But last month the drugmaker Sanofi said it still believes Acomplia can be a winner and reiterated plans to submit the drug worldwide as a treatment for type 2 diabetes in 2009.

Copyright 2008 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. All active hyperlinks have been inserted by AOL.
2008-05-08 12:28:17
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119 comments

decaff2 08:22:12 AM May 12 2008

What is the biggest problem people are having in this unstable world? Yep if you guessed WEIGHT LOSS Promises you are correct, as the biggest sellers of weight loss programs earn money from us to tell and show us how to do what we already know what to do with our weight, its the biggest on the internet, just try using weight.com and you will see just how many are out there to take are hard earned money for What? Their ideas which in some cases has caused many deaths from their so called secerts of loosing weight what people need are WEIGHTS used as in lifting not paying someone to show you how to eat. Just try a routine of using 3 lbs of weights in eachhand and get into a habbit, please people spend 20 bucks on a set of 2 ,5 and 8 pound weights from TJ Max. Run awyay from people trying to show you how to live your life with a price! Good Luck and God Bless.

esox4569 01:32:39 AM May 12 2008

How hard is it to watch what you eat and exercise. That is all there is to healthy and smart weight loss. The reason people want these magic pills is they want a quick fix. They have no will power. They want something without putting forth any effort. They want to be thin but yet be able to eat anything they want when they want. A person does not gain 20 pounds overnight. Common sense should tell people you can't take it off overnight either. Weight gain comes ************* of time and weight loss goes ************* of time. Anytime you try to speed up this process some part of the body is damaged.

rocketfamily6 07:02:54 PM May 11 2008

Taking pills for most things end up being more harmful. It's all about money to the pharms which are in cahoots w/the FDA. Western medicine is good for a broken bone or a ruptured appendix and such, but everything else...drug pushers. They don't fix problems, only mask them for a while in which time your body is being thoroughly poisoned. To lose weight, sure it's hard, but the only real answer is to not eat junk regularly and control your portions. Exercise and drink water. It works without a hitch or a rotten side-effect.

nadiazychal 06:21:58 PM May 11 2008

Drugs are not the answer to sensible weight loss!! Reasonable diet and excersize are and always will be. It's no surprise that people- and especially children- become obese when they eat corn syrup saturated soda for breakfast followed by a steady trough full of processed starchy cr*p all while sitting on their behinds all day playing world of warcraft. Get real. People need to take responsability for their own and their children's health by better behavior instead of drowning themselves in poison.

coloradosolar 05:59:47 PM May 11 2008

shoppincheril. you got it wrong ! test on politicians unsted of Rats

roseleepv 05:06:42 PM May 11 2008

I lost 90 pounds in one year on Herbalife. I am healthier than I have ever been! I have energy and I feel 20 yrs younger. I loved having the shakes and it was SOOOO EASY!!! The protien actually icreased muscle mass, I m Healthy and strong! And I feel Dynamite!
Dont take drugs to lose weight, You always lose good health as well.

mtnat 02:34:46 PM May 11 2008

masc930 04:06:58 PM May 09 2008

Report This! Some FDA-approved weight-loss drugs are extremely dangerous, too! One is Topamax. My psychiatrist prescribed Topamax for me, to counter the weight-gain side effect of Seroquel. I can honestly, and accurately, say the Topamax had a terrible effect on my brain. It caused me to have rage fits, in which I would mindlessly destroy things of my own, and be strongly tempted to destroy the property of others, as well. Fortunately, he stopped the Topamax--at my urging--before I could harm another person, or myself! I would not recommend Topamax for anyone--mentally ill or not!

_________________________
that stuff will kill yeah...!

mtnat 02:29:50 PM May 11 2008

oh heaven forbid we test on mice......i guess you folks name your *********** to....

if you only knew how medical lab tests that save lives came about.....just shows how in a box some people are...

bet you would be horrified if you even had a clue....

antiquerickon23 02:15:13 PM May 11 2008

I THINK IT IS CRUEL AND INHUMAN TO INJECT POOR HELPLESS ANIMALS FOR ANY REASON!!! IF PEOPLE WANT TO TAKE DRUGS TO LOSE POUNDS LET THEM TEST THE DRUGS... JUST EAT RIGHT AND GET OF THE COUCH!!

rkb7avg 01:10:09 PM May 11 2008

Having used diet pills for over 37 years daily and still do. I have found the older drugs still work the best .Phendimerazine is still one of the best meds. However our wonderfull government feels differently. So we continue reading every day how so many millions of americian people are so over weight. At 56 years of age at 5' 8 155 lbs I myself look and feel as good as I did when I was 30 years of age. Just food for thought.

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