Could targeting this heart hormone help control blood pressure?
Recent insights into a hormone released by muscle cells could lead to improved ways to treat high blood pressure.
When the hormone, which has the name atrial natriuretic peptide (ANP), enters the bloodstream, it lowers blood pressure by triggering blood vessel dilation and excretion of sodium in urine.
Scientists from the University of Copenhagen and Rigshospitalet in Denmark studied the function of ANP in rats.
They report their findings in a paper that features in the Journal of Biological Chemistry.
The team discovered that ANP's effect on blood pressure appears to depend on the presence or absence of a certain sugar molecule on the peptide.
"We can see," says study author Katrine Schjoldager, assistant professor in the Copenhagen Center for Glycomics at the University of Copenhagen, "that when that particular sugar is located on the peptide hormone, it regulates the fluid balance and blood pressure differently than if the sugar is not located there."
Molecular insights into blood pressure
The heart pumps blood around the body. This exerts pressure on the walls of arteries. If the pressure is too high or too low, it can cause health problems.
High blood pressure, or hypertension, affects around one in three adults, or 75 million people, in the United States, according to figures from the Centers for Disease Control and Prevention (CDC).
Having high blood pressure increases people's risk of developing heart disease or stroke, which are major killers in the US.
The new study is an example of glycoproteomics, a type of biological investigation that allows scientists to study glycosylation, or the way that cells tag different locations on proteins with sugar molecules to alter their function and make them stable.
Until recently, scientists did not have the tools to investigate the full scope of glycoproteomics.
In their study, Schjoldager and colleagues conducted a "comprehensive glycoproteomics analysis," using advanced technologies that included mass spectrometry and specialized software.
"In our animal models," Schjoldager notes, "we could see that the peptide hormone with and without sugar behaves differently."
A 'modern way to treat hypertension'
The researchers believe that their findings offer new insights into the regulation of blood pressure in the body.
Senior study author Jens Peter Gøtze, a professor in the Department of Clinical Biochemistry at Rigshospitalet, suggests that they could lead to a "modern way to treat hypertension without side effects, such as syncope [losing consciousness]."
He explains that scientists have known for some time that ANP is important for blood pressure, but until their findings, they had no clue about how it might serve as a target for treatment.
The researchers are planning a more detailed study of how the heart controls that particular sugar and where it attaches onto ANP.
After that, they want to find out how the function differs in humans with and without certain heart conditions, such as heart failure.
"This finding was only possible because we collaborated across disciplines and combined basic and clinical research."
-Prof. Jens Peter Gøtze
