CHARLOTTESVILLE, Va. — How does the human body keep your blood pressure so perfectly in check when healthy? The answer has eluded scientists for over 60 years — until now! A new study has discovered the missing link in blood pressure science that explains how the body knows how to prevent blood pressure from getting too high or too low.
A team from the University of Virginia School of Medicine says they have pinpointed the location of the body’s natural blood pressure barometers. These cellular sensors can detect even subtle changes in blood pressure and adjusts the body’s hormone levels accordingly.
Scientists first proposed the existence of these “baroreceptors” in 1957. Since then, researchers have believed that these blood pressure sensors are either inside or nearby specialized kidney cells called renin cells.
The new study, led by UVA Health’s Maria Luisa S. Sequeira-Lopez and colleagues, finally located the baroreceptors and reveals how they prevent both high blood pressure (hypertension) or low blood pressure (hypotension).
“It was exhilarating to find that the elusive pressure-sensing mechanism, the baroreceptor, was intrinsic to the renin cell, which has the ability to sense and react, both within the same cell,” says Sequeira-Lopez in a university release. “So the renin cells are sensors and responders.”
How does the body regulate your blood pressure?
Even before the discovery of the baroreceptors, scientists knew renin cells had to know when to release renin. This hormone helps to regulate blood pressure.
Sequeira-Lopez and her team used a combination of new lab models to determine that the baroreceptor is actually a “mechanotransducer” inside of renin cells. Researchers say this mechanism detects pressure changes outside the cell and transmits signals to the nucleus of cells. It’s a lot like how the cochlea of the ear turns sound vibrations into nerve impulses the brain recognizes.
In lab experiments, the team found that applying pressure to renin cells triggered changes in the renin gene, Ren1. Study authors discovered that when the baroreceptors detect too much pressure outside the renin cells, they send out signals which slow the production of the renin hormone. On the other hand, the baroreceptors signal for the renin cells to increase production when pressure drops.
“I feel really excited about this discovery, a real tour de force several years in the making. We had a great collaboration with Dr. [Douglas] DeSimone from the Department of Cell Biology,” Sequeira-Lopez adds. “I am also excited with the work to come, to unravel the signaling and controlling mechanisms of this mechanotransducer and how we can use the information to develop therapies for hypertension.”
The findings appear in the journal Circulation Research.