| Obesity continues to rise in the United States and | | | | gene-silencing technique called RNA interference |
| throughout the world. Both leptin from fat cells | | | | allowed Dr. Clegg to shut down the alpha |
| and insulin from pancreatic B cells are created in | | | | receptors in the VMN of female rats. The |
| direct proportion to body fat. Obese persons | | | | estrogen receptors in other regions of the brain |
| have higher levels of these two hormones than | | | | were not affected. As estrogen levels decreased, |
| lean individuals. Recent studies show that another | | | | so did the metabolic rate and energy levels. The |
| hormone, estrogen, also has a similar affect. | | | | rats quickly became glucose intolerant. While their |
| When estrogen receptors in the hypothalamus of | | | | caloric intake did not change, they gained |
| rats were destroyed, female rats ate more food, | | | | considerable abdominal weight. |
| burnt less energy and became obese. Research | | | | Dr. Clegg feels that deactivating ERa in the |
| suggests a link between estrogen and obesity, | | | | arcuate nucleus region of the hypothalamus may |
| especially the dangerous accumulation of | | | | have the same effect. There are two groups of |
| abdominal fat linked to cardiovascular disease, | | | | neurons in this region. One reduces food intake |
| type-2 diabetes mellitus, and certain cancers. The | | | | and the other stimulates it. Estrogen loss in this |
| abstract was submitted by Deborah J. Clegg, PhD, | | | | region may increase both appetite and weight. |
| Assistant Professor of Psychiatry, Obesity | | | | In humans, the accumulation of abdominal fat in |
| Research Center, at the University of Cincinnati | | | | men and women increases their risk of |
| Academic Health Center, to the 234th national | | | | cardiovascular disease, diabetes, and insulin |
| meeting of the American Chemical Society on | | | | resistance. Young women are protected from |
| August 20, 2007. Her findings will assist scientists | | | | these risks while they carry their weight in their |
| in developing new hormone replacement therapies. | | | | hips and saddlebags. With the onset of |
| Dr. Clegg Estrogen wanted to determine the | | | | menopause, however, body fat is stored in the |
| effect of reduced estrogen levels in the brain. She | | | | abdomen, increasing the risk of medical |
| investigated estrogen receptor alphas (ERa) in the | | | | complications. By identifying the critical brain |
| hypothalamus, where the brain regulates body | | | | regions and estrogen receptors associated with |
| temperature, hunger and thirst. She learned that | | | | weight gain and energy expenditure, scientists will |
| the ventromedial nucleus (VMN) and the arcuate | | | | one day be able to design hormone replacement |
| nucleus respond to hormones and other signals to | | | | therapies that will help women avoid many of the |
| control energy intake and expenditure. A | | | | risks associated with the onset of menopause. |