MICHIGAN STATE (US) — Long-term exposure to estrogen generates excessive levels of a compound that increases stress, ultimately causing a rise in blood pressure.
But new findings, published in the American Journal of Physiology, suggest that the anti-oxidant resveratrol reverses the increase in both the compound, superoxide, and subsequently the blood pressure as well.
“This is an important study on at least two levels,” says P.S. MohanKumar, associate professor of pathobiology and diagnostic investigation at Michigan State University. “First, it continues to confirm the negative effect that long-term estrogen exposure has for females. Second, it provides a new rationale for how and why this relationship occurs.”
MohanKumar and colleagues looked to the rostral ventrolateral medulla, a critical region in the brain stem involved with the maintenance of blood pressure and thought to be associated with hypertension and heart failure.
Believing that chronic exposure of estrogen could influence this area of the brain, they conducted a two-phase experiment using rats, injecting them first with estrogen and then also feeding them the anti-oxidant resveratrol.
Chronic exposure caused a significant increase in superoxide in the rostral ventrolateral medulla and in blood pressure. Resveratrol reversed those increases.
“Because so many women use estrogen-only HRT to combat the effects of menopause, it is imperative that we better understand the risks that chronic exposure has for females and why these effects occur,” says MohanKumar.
“In studies such as this, we come one step closer to clarifying the relationship and have established a launch pad for identifying how the process might be interrupted in the future.”
More news from Michigan State University: http://news.msu.edu/