Dementia, high blood pressure and brain blood flow may be linked

Sep 29, 2010
Dementia, high blood pressure and brain blood flow may be linked

Blood flow through the brain is essential for the delivery of nutrients such as glucose and oxygen that are needed for nerve cells to function. During the early stages of Alzheimer's disease (AD) patients can suffer from high blood pressure and blood flow through the brain is reduced: the greater the reduction, the worse patients' dementia becomes.

A new study will look at the relationship between dementia and high blood pressure, and how is regulated in the brain. The findings may help researchers identify if some drugs already used for other human conditions may be useful for the treatment of diseases such as stroke and Alzheimer's disease (AD).

Academics at Bristol University's Dementia Research Group, based at Frenchay Hospital, have been awarded a grant of over £266,000 from the British Heart Foundation (BHF) to assess whether drugs that block a small naturally produced molecule called endothelin-1 can improve blood flow through the brain.

In animal models of AD a reduction in blood flow occurs well before the onset of Alzheimer-like damaging changes to .  The most potent cause of the narrowing of is a small molecule called endothelin-1 (ET-1).  This molecule is produced by the action of endothelin-converting enzymes (ECEs).

The Bristol-based academics recently found that ECE-2 in the brain of AD patients was abnormally high.  One of the hallmarks of AD is the large amount of amyloid β, a toxic molecule which accumulates in the brain of AD patients.  The Bristol-based researchers have shown that ECE-2 production increased when were exposed to amyloid β, long before people start to display the memory problems recognised in AD.  The academics therefore suggested that an important cause of reduced blood flow through the brain in AD (and to , which has been linked to AD) is likely to be an increase in ET-1, resulting from the stimulatory effect of amyloid β on ECE-2 production.

Seth Love, Professor of Neuropathology, said: "We hope our study will shed light on the role of amyloid β.  We know it to be involved in AD but it is produced throughout life and what it does in the normal brain has long been a mystery.

"In addition, our research could have important implications for control in people with hypertension as well as for treatment of diseases such as stroke and where effective treatments remain limited.  Drugs that block ET-1 are already licensed for the treatment of other human diseases and could be used to treat people who have elevated levels of amyloid β and increased ECE-2 activity, whether in the context of established AD or , or at an earlier stage prior to the development of irreversible brain damage."

Professor Jeremy Pearson, Associate Medical Director at the BHF, added: "Thanks to the generous donations of our supporters in Bristol we're able to fund vital research to fight diseases of the heart and circulation.  This latest grant joins our portfolio of world-leading research to improve prevention, diagnosis, treatment and care of heart diseases."

Explore further: US scientists make embryonic stem cells from adult skin

add to favorites email to friend print save as pdf

Related Stories

Blood flow in Alzheimer's disease

Jul 27, 2009

Researchers have discovered that the enzyme, endothelin converting enzyme-2 (ECE-2), may cause the decrease in blood flow in the brain seen in Alzheimer's disease and contribute to progression of the disease.

Investigating the causes of Alzheimer's

Nov 22, 2007

Scientists at the University of Bristol are investigating what causes the leaks that develop in blood vessels in Alzheimer's disease, thanks to funding from the UK's leading dementia research charity, the Alzheimer's Research ...

Mechanism links abnormal blood clots with Alzheimer's disease

Jun 09, 2010

New research suggests that abnormalities in the process of blood clot formation may contribute to the pathogenesis of Alzheimer's disease (AD). The study, published by Cell Press in the June 10 issue of the journal Neuron, advanc ...

Recommended for you

Leeches help save woman's ear after pit bull mauling

Apr 18, 2014

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

New pain relief targets discovered

Apr 17, 2014

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

User comments : 0

More news stories

Treating depression in Parkinson's patients

A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.