Mar 4 2008
British scientists say they may have found a new way to treat obesity by stopping the stomach from expanding.
The scientists from University College London have identified two cell proteins P2Y1 and P2Y11 that relax the gut and help it to accommodate a big meal.
They theorise that a drug which blocked this relaxation would reduce a person's ability and desire to gorge on excessive amounts of food, in other words a pill to treat obesity without the need for risky surgery.
The expansion is controlled by nerves inside the stomach wall which release molecules that stimulate P2Y1 and P2Y11 embedded in muscle cells and also in the gut wall.
The human stomach has a "resting" internal volume of 75 millilitres, but by relaxing its muscular wall it allows its capacity to increase 25-fold from three fluid ounces to around four pints.
According to researcher Dr. Brian King the mechanism of slow relaxation of the stomach might represent a future drug target in the fight to control weight gain and reverse obesity.
Dr. King says they are looking for drugs that would block the P2Y11 receptor and, therefore, prevent slow relaxation of the stomach; if the P2Y11-based mechanism was blocked the meal size would be smaller and the person would have a better chance of regulating their food intake.
Dr. King says this would represent a new approach to weight control as at present difficult surgical procedures such as gastric banding or stomach stapling are used to reduce the maximum volume of the stomach and they carry a risk of serious side effects.
Experts agree that an alternative treatment for obesity would be useful as major surgery such as gastric banding was expensive and risky.
They say while current drugs that focus on appetite suppression, or on reducing fat absorption by the body did work, their long term effects remains unclear and there much still has to be learned about the complex way appetite and food intake is controlled.
Dr. King says the research is still in the early stages and any new pill is a decade away from the market.
Adult obesity rates worldwide have soared in recent years particularly in developed countries.
The World Health Organisation (WHO) found globally in 2005 that approximately 1.6 billion adults (age 15+) were overweight; at least 400 million adults were obese and by 2015, approximately 2.3 billion adults will be overweight and more than 700 million will be obese.
In 2005 globally at least 20 million children under the age of 5 years were overweight.
The WHO says while it was once considered a problem affecting only high-income countries, overweight and obesity are now dramatically on the rise in low- and middle-income countries, particularly in urban settings.
Experts say that unless urgent action is taken, an entire generation faces an old age blighted by heart disease, cancer, diabetes and other diseases brought on by obesity.
The University College London study appears in the Journal of Pharmacology and Experimental Therapeutics.
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