May 7, 2008
Inhibiting Brain Enzyme May Help Weight Loss
New findings of a U.S.-based study showed that blocking a single brain enzyme caused mice to eat less and maintain better blood glucose levels.
Researchers hope the results will lead to new improvements in the treatment of obesity and diabetes in humans.
"We believe we have identified an important drug development target that could potentially turn into a metabolic triple play: appetite control, weight loss and blood sugar management," said Tony Means of Duke University Medical Center in Durham, North Carolina.
Researchers found that inhibition of an enzyme named CaMKK2 slowed appetite and promoted weight loss.
Additionally, blocking CaMKK2 protected mice from high-fat diet-induced obesity, insulin resistance and glucose intolerance.
Recent studies have shown a link between the role played by the central nervous system, namely the hypothalamus, in moderating food intake, energy expenditure and glucose metabolism, researchers wrote in the journal Cell Metabolism.
People dealing with diseases such as hypertension, cardiovascular disorders, certain cancers and type 2 diabetes, caused by obesity, could stand to benefit from new developments in enzyme blocking methods.
Researchers at the Neurological Institute at McGill University in Montreal found a hormone called gherlin, released in the stomach, linked to appetite control.
Means' team hopes to find a way to interrupt ghrelin's activity by toning down the CaMKK2 enzyme's response to the hunger signal.
Mice genetically engineered to lack the enzyme CaMKK2 stayed slim regardless of whether they were on a low-fat or high-fat diet.
"They don't gain as much weight as wild type mice," Means said.
The most difficult job facing researchers is to find a drug that can be given to patients orally and still reach the right target in the brain.
Many chemicals are not able to cross the blood brain barrier, a special characteristic of blood vessels feeding the brain that filters out toxins.
"The job will be to identify one that will pass the blood brain barrier," Means said.
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Duke University Medical Center
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