Biological trigger for high blood pressure found
13 Jun 2012 by Evoluted New Media
A biological tipping point in the development of high blood pressure may have been discovered by researchers at St George’s University of London.
The team discovered that the reduced activity of a potassium channel called Kv7.4 – which is involved in keeping the arteries relaxed – may be a fundamental step in the development of high blood pressure. They found the channel is present in the renal artery – the main artery supplying blood to the kidney – and believe that reduced levels of activity here could kick-start a chain reaction inside the body that is known to increase blood pressure.
In laboratory studies, the team examined the hypothesis that Kv7.4 channels contribute to ?-adrenoceptor-mediated vasodilation in the renal vasculature in spontaneously hypertensive rats. They showed that when the channel is disabled, the body does not react to triggers like adrenaline which tell the artery to widen, and blood flow becomes constricted.
While the impact of this in one or two arteries is unlikely to cause high blood pressure, the fact that Kv7.4 channel is present in the renal artery leads researchers to believe that this could act as a tipping point for high blood pressure.
“If the Kv7.4 channels dilate arteries to lower blood pressure in the way we think they do then the identification that they underlie the relaxation caused by naturally occurring hormones such as adrenaline mean that, eventually, we may be able to target these channels to influence blood pressure,” said Dr Iain Greenwood, who led the research.
The study – published in Hypertension – provides the first evidence that Kv7.4 channels contribute to ?-adrenoceptor-mediated vasodilation in renal vasculature. The researchers say more investigations are needed before treatment can be developed from their findings. However, this shift in understanding how high blood pressure develops could be the cornerstone of new treatment.
