High blood pressure could be a brain problem

Apr 16 2007

Scientists in Britain say the cause of high blood pressure may lie within the brain, rather than with problems relating to the heart, kidneys or blood vessels.

The scientists at Bristol University say their discovery could lead to new ways of treating the condition which affects about one in five Britons.

The team have isolated a protein, JAM-1,which is located in the walls of blood vessels in the brain.

JAM-1 appears to trap white blood cells called leukocytes which can obstruct the blood flow which in turn can cause inflammation and result in poor oxygen supply to the brain and these events can trigger the raised blood pressure.

According to lead researcher Professor Julian Paton and colleagues, though the exact mechanisms remain unclear, their studies in rats indicate that JAM-1 is linked to raised blood pressure and they are now looking at the human brain in order to gain a better understanding.

Professor Paton believes the challenge in future will be to understand the type of inflammation within the vessels in the brain, so that effective drugs can be used to target them.

Paton says JAM-1 could provide new clues in how to deal with the disease especially in patients that fail to respond to conventional therapy for hypertension by using drugs that reduce blood vessel inflammation and increase blood flow within the brain.

Experts at the British Heart Foundation, which funded the work, say the study is exciting because it suggests there are unexpected causes of high blood pressure related to blood supply to the brain which will possibly offers new ways to treat the common, but often poorly managed, condition.

That the brain can affect blood pressure is not a novel idea, a team of researchers at John Radcliffe Hospital in Oxford found they could affect patients' blood pressure and increase or decrease it by stimulating very specific regions of the brain with electrodes.

But experts caution that the work is at the preliminary stage and much more research is needed and blood pressure medicines currently prescribed by doctors can be very effective, provided they were taken correctly and in combination with leading a healthy lifestyle.

High blood pressure, or hypertension, can cause headaches, dizziness and problems with vision, but the majority of people with the condition do not display any noticeable symptoms.

Hypertension can lead to heart attack, stroke and kidney damage, but medication can be used to control its effects if changes to lifestyle fail to lower blood pressure.

In the UK alone one in three people are likely to develop hypertension, and 600 million people are affected world wide.

The research is published in the current issue of the journal Hypertension.