September 1, 2006

Stress may promote the progress of Alzheimer's disease

Stress may hasten Alzheimer's
IRVINE, Calif., Aug. 30 (UPI) -- Stress hormones may exacerbate the formation of brain lesions that are the hallmarks of Alzheimer's disease, according to California researchers.

Frank LaFerla led a team of University of California at Irvine researchers that found that when young animals were injected for just seven days with dexamethasone -- similar to the body's stress hormones -- the levels of the protein beta-amyloid in the brain increased by 60 percent. When beta-amyloid production increases and these protein fragments aggregate, they form plaques, one of the two hallmark brain lesions of Alzheimer's disease. They also found that the levels of another protein, tau, also increased. Tau accumulation eventually leads to the formation of tangles, the other signature lesion of Alzheimer's.

"It is remarkable that these stress hormones can have such a significant effect in such a short period of time," LaFerla said. "Although we have known for some time that higher levels of stress hormones are seen in individuals in the early stages of Alzheimer's, this is the first time we have seen how these hormones play such a direct role in exacerbating the underlying pathology of the disease."

The findings, published in the Journal of Neuroscience, suggest that managing stress and reducing certain medications that contain glucocorticoids could slow down the progression of Alzheimer's.

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