CincinnatióResearchers at the University of Cincinnati (UC) College
of Medicine are trying to determine if what started as an advantageous
genetic mutation in native Africans may cause hypertension in blacks in
the United States. According to Anil Menon, PhD, associate professor of
molecular genetics, individuals in Africa developed a variant in the
gene that controls the transport of sodium. People with this variant
gene known as the sodium channel gene, conserve more sodium and water
in their bodies to help them survive the heat and arid conditions of
More than 30 years ago, researchers thought that
these arid conditions might account for the increased selection of
variant genes for salt and water conservation in these populations. The
additional sodium and water in the body increases blood volume,
resulting in high blood pressure.
The sodium channel in the
kidney is a crucial control point for the balance of water, sodium, and
hypertension. Researchers in Menon's lab have found a variation in this
channel that is present in people of African ancestry. The UC team of
researchers include Yan Ru Su, MD, molecular genetics research
associate; Max Reif, MD, associate professor of internal
medicine/hypertension; Raymond Pun, PhD, molecular and cell physiology
research associate professor; and post doctoral fellow Shodimu Olufemi.
These researchers believe that the genetic predisposition to
hypertension in African Americans may extend to other desert
populations such as Arabians and South American desert Indians.
research combines genetics and physiology to understand the role of
sodium and fluid retention. More importantly, it may shed light on why
African-Americans have a greater incidence of high blood pressure. "We
know that high blood pressure increases the risk of heart attacks,
strokes, kidney failure, and certain kinds of blindness," says Menon.
"Knowing more about genetic influences will help us design better,
individual-specific drug treatments for cardiovascular disease."