Study Shines Light on How Red Blood Cells Control Blood Pressure

October 21, 2008

(PhysOrg.com) -- A new technique sheds light on how red blood cells regulate blood pressure in small blood vessels.

A clear understanding of blood-pressure regulation could help development of treatments for diseases such as cystic fibrosis, pulmonary hypertension, diabetes and cancer. The researchers' findings appear online this month in the journal Proceedings of the National Academy of Sciences.

Human red blood cells are believed to play a key role in the regulation of blood pressure by means of an intricate mechanism that involves force from blood flow, biochemical signals and the protein configuration of the cell membrane. The details of this process, however, have been unclear.

"Not only will this new tool be important in developing a fundamental understanding of blood-cell behavior in response to different therapeutics, it also provides a way to probe how different foods may affect red blood cells' ability to micro-regulate blood pressure and, consequently, overall health," said co-author William Ristenpart, an assistant professor in the Department of Chemical Engineering and Materials Science at UC Davis.

Ristenpart, who also has a joint appointment in UC Davis' Department of Food Science and Technology, participated in this study as a postdoctoral fellow at Harvard University.

Human red blood cells can regulate blood pressure by releasing the chemical ATP (adenosine triphosphate), which triggers the blood vessel to expand. Previous studies have indicated that the release of ATP is related to "shear stress," the frictional force created by the flow of blood through the blood vessel. Although previous work suggested that shear stress deforms the shape of the red blood cells and triggers ATP release, it was not known just how much ATP was released by different levels of deformation.

Ristenpart, and colleagues Jiandi Wan and Howard Stone at Harvard University, set out to study this process by forcing red blood cells through a microscopically small synthetic vessel that narrowed and then widened again, mimicking the passage of red blood cells through a constricted blood vessel. They used the light-emitting enzyme luciferase, which binds with ATP, to follow the timing and amount of ATP released by the red blood cells with millisecond resolution.

The researchers found that there was a considerable lag time from when the red blood cells first experienced increased shear stress to when they released ATP, and that an increase in shear stress resulted in a quicker and greater release of ATP.

The researchers also found that the length of time it takes the cell to change shape as it passes through a narrowed passageway signals how much ATP the cell should release. Contrary to their expectations, they found that elongation of the cells by as much as 40 percent was insufficient to trigger any ATP release if the elongation lasted less than 3 milliseconds.

The researchers suspect that the ATP-release mechanism is tied to the contraction and relaxation of the protein network that makes up the red blood cell's outer membrane.

Provided by UC Davis

Explore further: Definitive global transfusion study supports patient safety, positive patient outcomes

Related Stories

Definitive global transfusion study supports patient safety, positive patient outcomes

November 13, 2017
Lower thresholds for blood transfusions during cardiac surgery have proven to be safe and provide good patient outcomes compared to traditional thresholds, according to the largest research study ever performed in this area. ...

Study finds less blood can be used in heart operations

November 13, 2017
Heart surgery requires more blood transfusions than almost any other surgical procedure.

Sickle cell patients suffer discrimination, poor care—and shorter lives

November 13, 2017
For more than a year, NeDina Brocks-Capla avoided one room in her large, brightly colored San Francisco house - the bathroom on the second floor.

Fewer heart surgery patients may have to be exposed to blood transfusions, researchers say

November 13, 2017
Not as many heart surgery patients may need to be exposed to the potential dangers of blood transfusions, according to a new study that researchers say may change current practice.

Genetic mutation in extended Amish family in Indiana protects against aging and increases longevity (Update)

November 15, 2017
The first genetic mutation that appears to protect against multiple aspects of biological aging in humans has been discovered in an extended family of Old Order Amish living in the vicinity of Berne, Indiana, report Northwestern ...

Study finds that heart failure is more fatal in patients with type 2 diabetes

November 17, 2017
A new study has found that heart failure patients with pre-existing type 2 diabetes have higher hospitalisation and death rates, but that keeping blood sugars balanced can help lower the risk almost to that of heart failure ...

Recommended for you

Hibernating ground squirrels provide clues to new stroke treatments

November 17, 2017
In the fight against brain damage caused by stroke, researchers have turned to an unlikely source of inspiration: hibernating ground squirrels.

Age and gut bacteria contribute to multiple sclerosis disease progression

November 17, 2017
Researchers at Rutgers Robert Wood Johnson Medical School published a study suggesting that gut bacteria at young age can contribute to multiple sclerosis (MS) disease onset and progression.

Molecular guardian defends cells, organs against excess cholesterol

November 16, 2017
A team of researchers at the Harvard T. H. Chan School of Public Health has illuminated a critical player in cholesterol metabolism that acts as a molecular guardian in cells to help maintain cholesterol levels within a safe, ...

Prototype ear plug sensor could improve monitoring of vital signs

November 16, 2017
Scientists have developed a sensor that fits in the ear, with the aim of monitoring the heart, brain and lungs functions for health and fitness.

Ancient enzyme could boost power of liquid biopsies to detect and profile cancers

November 16, 2017
Scientists are developing a set of medical tests called liquid biopsies that can rapidly detect the presence of cancers, infectious diseases and other conditions from only a small blood sample. Researchers at The University ...

FDA to crack down on risky stem cell offerings

November 16, 2017
U.S. health authorities announced plans Thursday to crack down on doctors pushing stem cell procedures that pose the gravest risks to patients amid an effort to police a burgeoning medical field that previously has received ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.