Weight, Energy Expenditure and 5-HT(2c)
Brain Cell Receptor
Weight Loss Study Summary
In a recent weight loss study, researchers have identified a physiological
process that may contribute to obesity in middle-aged mice. They suspect
the same process occurs in humans and could be a factor in the weight
gain that many people experience as they age. The finding suggests a possible
target for weight gain therapy.
Weight Loss Study - Burn Less Calories
Researchers determined that middle-aged mice expended less energy - i.e.,
burned fewer calories - to carry out the same physical activity - scurrying
to and fro - than younger adult mice. The most dramatic findings were
seen in a comparison of middle-aged and younger-adult mice genetically
engineered to lack a brain cell receptor known as 5-HT(2c), which receives
signals from the brain chemical serotonin.
Weight Loss Study - Middle Age Weight
Gain
Traditionally, scientists have surmised that the increase in weight gain
seen in middle-aged mammals, including mice and people, was due in part
to declines in resting metabolic rate and physical activity levels. However,
in the study, both sets of middle-aged mice ate the same amount, had the
same resting metabolic rate and had the same level of activity as their
younger brethren. The only difference was the increased efficiency with
which both groups of middle-aged mice burned calories during exercise.
In other words, they got more miles per gallon.
Weight Loss Study - Serotonin
The energy-expenditure mechanism could prove a target for weight loss
therapy. A possible candidate for such a target is the serotonin 5-HT(2c)
receptor. Mice genetically engineered to lack the 5-HT(2c) serotonin receptor
demonstrated the most dramatic results in the study. Middle-aged normal
mice, which gradually gain weight as they age, burned less energy during
activity than younger normal mice, despite eating the same moderate amount
of food and maintaining the same resting metabolic rate.
Source: 2003 Aphroditewomenshealth.com
|
|
|
com