Bethesda, Md. (May 26, 2011)For many years doctors believed the estrogen women consumed in the form of oral contraceptives and hormone replacement therapy (HRT) pills was good for their patients' hearts. Recent studies however have shown that long-term exposure to estrogen can be a danger to women as it has been associated with high blood pressure, a key link to heart- and brain-attacks (strokes). Although the process by which estrogen induces high blood pressure in females is unclear, Michigan State University (MSU) researchers have found that long-term estrogen exposure generates excessive levels of a compound, superoxide, which causes stress in the body. The build-up of this compound occurs in an area of the brain that is crucial to regulating blood pressure, suggesting that chronic estrogen induces a build up of superoxide that in turn causes blood pressure to increase. The study also found that the anti-oxidant resveratrol reverses the increase in both superoxide and blood pressure.
The study is entitled Chronic Estradiol-17β Exposure Increases Superoxide Production in the Rostral Ventrolateral Medulla (RVLM) and Causes Hypertension: Reversal by Resveratrol." It appears in the Articles in PresS section of the American Journal of Physiology Regulatory, Integrative, and Comparative Physiology, published by the American Physiological Society.
The researchers looked to the rostral ventrolateral medulla (RVLM), a critical region in the brain stem known to be involved with the maintenance of blood pressure and thought to be associated with hypertension and heart failure. They theorized that chronic exposure to low levels of estrogen (in the form of estradiol-17β, also called E2) could influence this area of the brain. They hypothesized that E2 exposure could increase the anti-oxidant superoxide, which causes stress in the body and the RVLM to respond by increase the body's blood pressure. They also wan
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American Physiological Society