Scientists have bred a new kind of rat that will help them to study the effects of lower levels of estrogen in postmenopausal women that can lead to hypertension and heart failure.
Researchers at Wake Forest University School of Medicine have created a better research rat by changing a single gene that is involved in hypertension. These rats will allow them to study salt-sensitivity in hypertension as well as explore how estrogen depletion affects several body systems.
The researchers are presenting three reports on their research at the American Heart Association's 59th Annual Fall Conference and Scientific Sessions of the Council for High Blood Pressure Research in Washington, D.C.
In the study the team had looked at how estrogen depletion affects diastolic heart dysfunction. In this common form of heart failure, the heart muscle becomes stiff and cannot fill with enough blood to meet the body's demands. Diastolic dysfunction is more common in women after menopause and is frequently associated with hypertension.
In these rats, the researchers found that estrogen depletion exacerbates the progression of diastolic dysfunction. Scientists have long known that estrogen helps protect heart vessels from atherosclerosis, the buildup of fatty deposits that can cause heart attacks. This research suggests that it may also protect heart function.
The researchers had tried to determine if estrogen is also protective against the hypertension and renal damage that arises from excess salt in the diet. In the rats fed a high salt diet, estrogen depletion increased blood pressure and exacerbated renal injury. The lack of estrogen resulted in increase levels of a hormone called aldosterone that may contribute to both diastolic dysfunction and kidney injury.