Wednesday, January 26, 2005
Secret to diabetes treatment may lie in the brain
Researchers say that the fat hormone leptin may be able to control blood sugar levels by acting through a particular region of the brain. Preliminary experiments in mice indicate that the hormone may be the key to new treatments for type II diabetes. It might also lead to new insights into obesity.


Overview:



New research published in the premier issue of Cell Metabolism finds that a single brain region is sufficient for normal control of blood sugar and activity level by the fat hormone leptin.
The same region also exerts significant, though more modest, control over leptin's effects on body weight.
The findings in mice provide insight into potential mechanisms underlying type II diabetes and suggest new avenues for treatment, according to the researchers.
Secreted by fat cells, leptin signals the status of the body's energy content to the brain and is required for normal body weight and glucose balance.
Mice lacking leptin develop obesity, diabetes, and inactivity, among other symptoms.
The new results suggest that leptin signaling acts directly on the brain region known as the hypothalamic arcuate nucleus (ARH) to control insulin and glucose levels in the bloodstream, report Joel Elmquist and Bradford Lowell, both of Beth Israel Deaconess Medical Center and Harvard Medical School, and their colleagues.
ARH neurons also mediate the majority, if not all, of the hormone's action on locomotor activity, they found.
Leptin receptors in the ARH accounted for approximately 22 percent of the hormone's effects on body weight, the group reports, suggesting that other brain regions are also important to this hormonal function.
Restoration of leptin signaling also remarkably improved glucose homeostasis in the mice.
Eight weeks after the treatment, blood glucose levels in the mice were indistinguishable from normal mice of the same age.
The restored mice also exhibited significant increases in locomotor activity compared to leptin-deficient mice.
While earlier studies had shown that leptin acts primarily through its effects on the central nervous system, the findings provide important new details about which brain areas mediate each of the fat hormone's many actions, the researchers said.

Source: http://www.innovations-report.de/ht...icht-39020.html