Scientists have discovered a brain enzyme that has opened up new paths for tackling obesity.health and fitness Updated: Mar 18, 2004 20:07 IST
A brain enzyme has opened up new paths for tackling obesity, a problem that has reached epidemic proportions in wealthy western countries.
AMP-activated protein kinase (AMPK) has long been identified as a "fuel gauge" to monitor energy levels in cells.
Working on a hunch that AMPK's role may be wider than this, US scientists injected leptin, an appetite-suppressing hormone that also blocks the action of AMPK, into a brain region called the hypothalamus in lab mice.
The AMPK-inhibited rodents lost weight, while a control group that had received only a saline injection slightly gained in weight.
AMPK is clearly part of the molecular cascade that triggers the desire to eat or not, the authors suggest.
"Suppression of AMPK activity in the medial hypothalamus is necessary for leptin's anorexic and weight-loss effects," they say.
"Lack of suppression causes leptin resistance," a condition that contributes to obesity.
The research, led by Barbara Kahn of the Beth Israel Deaconess Medical Center and Harvard Medical School is published on Thursday in Nature, the British weekly science journal.
It is the latest study to uncover a hormone, enzyme or genetic cause for obesity.
Such discoveries open doors to potential treatment based for instance on the principle of blocking the substance that causes unwanted weight gain.
However, there is usually a very long road in pharmaceutical research before any of these treatments enter the public domain.
Excess fat is most prevalent in the United States, where almost 130 million people, or 64 percent of the population, are overweight or obese.
But some European countries, notably Britain, are following the same path, and fast-growing Asian countries are not far behind.