Obese Rats Successfully Treated With Addiction Drug

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Main Category: Obesity / Weight Loss / Fitness
Also Included In: Alcohol / Addiction / Illegal Drugs
Article Date: 22 Aug 2008 - 9:00 PDT

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US scientists testing the epilepsy drug vigabatrin (GVG) as a potential treatment for drug addiction, discovered that it also led to rapid weight loss and reduced food intake in genetically bred obese rats.

The discovery by scientists at the US Department of Energy's (DOE) Brookhaven National Laboratory, is published in the 20 August advance online issue of the journal Synapse.

Vigabatrin is currently being tested throughout the US in Food and Drug Administration (FDA) approved Phase II trials for the treatment of cocaine and methamphetamine addiction.

For this latest study, the scientists at the DOE's Brookhaven Laboratory found that rats that were genetically bred to be obese showed a 19 per cent loss of total body weight while rats that were not obese lost 12 to 20 per cent, after less than two months on vigabatrin.

Study leader Amy DeMarco, who works with co-author and senior scientist at the Laboratory, Stephen Dewey, said it appeared that the drug made the animals feel full:

"Our results appear to demonstrate that vigabatrin induced satiety in these animals."

Dewey's team was the first to discover vigabatrin as a potential treatment for addiction. They have been investigating the drug for more than 20 years.

Earlier research at Brookhaven discovered a strong link between obesity and addiction, characterized by similar changes in brain activity of the obese and addicts depedent on drugs like cocaine. This prompted Dewey and colleagues to try and find out if vigabatrin would quench food cravings as it does drug cravings. As Dewey explained:

"Given the growing obesity epidemic, we felt that examining vigabatrin's therapeutic efficacy for obesity was particularly relevant."

For the study, Dewey, DeMarco and colleagues assigned 50 adolescent and adult genetically bred "fat" and normal weight rats either to a control group or to groups that were given varios doses of vigabatrin and monitored them for up to 40 days.

The control group rats were given daily injections of saline, while the drug groups were injected with up to 300 mg of of vigabatrin a day. The injection phases lasted for two periods of 7 to 13 days, with breaks in between.

After 40 days, all the animals treated with vigabatrin weighed significantly less than those that received only the saline injections (the controls).

The biggest weight loss and reduction in food intake was in the group that had the biggest dose, the 300 mg dose of vigabatrin. The obese rats lost an average of 19 per cent of their body weight, and the non obese animals lost between 12 and 20 per cent.

Dewey said that the fact the results occurred in the genetically obese animals "offers hope that this drug could potentially treat severe obesity".

"This would appear to be true even if the obesity results from binge eating, as this disorder is characterized by eating patterns that are similar to drug- taking patterns in those with cocaine dependency," he added.

"Subchronic racemic gamma vinyl-GABA produces weight loss in Sprague Dawley and Zucker fatty rats."
Amy DeMarco, Reema M. Dalal, Milan Kahanda, Uma Mullapudi, Jessica Pai, Crystie Hammel, Courtney N.B. Liebling, Vinal Patel, Jonathan D. Brodie, Wynne K. Schiffer, Stephen L. Dewey, Stefanie D. Aquilina
Synapse Published Online: Aug 20 2008, (p 870-872).
DOI: 10.1002/syn.20555

Click here for Abstract.

Sources: Journal abstract, Brookhaven National Laboratory.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
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