By removing a set of nerve connections in the necks of rats, scientists have discovered a way to treat hypertension — commonly known as high blood pressure — drug-free.
The study, which was recently published the journal Nature Communications, found that a nodule on the rats’ carotid artery in the neck, called the carotid body, had certain links to the animals’ brains so that when researchers removed the link, the rats’ blood pressure fell and remained low. These results show considerable promise for future trials on humans, a potential landmark in treating the condition, which affects roughly one in every three people worldwide.
Lead researcher of the study, Dr. Julian Paton of Britain’s Bristol University, remarked that scientists have long known about the link between the carotid bodies and high blood pressure; however, they “had absolutely no idea that they contributed so massively to the generation of high blood pressure,” Reuters reports.
Carotid bodies help regulate blood pressure in their interplay with levels of oxygen and carbon dioxide. When levels fall too low, the chemoreceptors raise blood pressure to increase breathing and distribution of oxygen throughout the body. Blocking the nervous system’s receptors to the brain resulted in prolonged drops in blood pressure, as the carotid bodies could not properly communicate the signal.
Carotid sinus denervation (CSD) “remains effective, producing a summative response indicative of an independent mechanism,” the researchers concluded. “Our findings indicate that CB de-afferentation is an effective means for robust and sustained sympathoinhibition, which could translate to patients with neurogenic hypertension.”
Precisely, the disconnect between nerves and brain is what Tony Heagerty, a professor of medicine at Manchester University who was not involved in the study, said could allow humans to “potentially avoid the use of drugs which have to be taken on a daily basis for many years."
Paton’s team has already begun work on a small human trial, the results of which are slated to arrive at the end of this year. If successful, the trial could revolutionize the way hypertension currently sees treatment.
In addition to dietary changes — more whole-grain breads, less salt, and limited alcohol consumption — a healthcare provider may prescribe medication to reduce the condition’s severity. These medications typically include ACE inhibitors, ARBs, beta blockers, diuretics, and calcium channel blockers. While their mechanisms may differ, most hypertension medications are designed to relax the blood vessels, either through hormonal shifts or chemical changes.
If left unabated, high blood pressure could result in heart attack, stroke, or diabetes. People with high blood pressure won’t know they have it until a physician checks specifically, making it particularly dangerous for people whose lifestyle has remained unhealthy for long stretches of time.
Source: McBryde F, Abdala A, Hendy E. The carotid body as a putative therapeutic target for the treatment of neurogenic hypertension. Nature Communications. 2013.