Arterial hypertension, a common and often symptomless condition, could have more complex mechanisms than previously thought. A new study indicates that certain processes in the brain could directly contribute to the increase in blood pressure, opening up the prospect of different therapeutic approaches.
The scientists analyzed the role of a region in the brainstem called the lateral parafacial region, part of the brain’s oldest structure, responsible for automatic functions such as breathing, digestion and heart rate.
This region is involved in forced exhalations, such as those during laughing, physical exertion or coughing. These expirations are generated by the contraction of the abdominal muscles, unlike normal breathing, in which the air is passively eliminated, due to the elasticity of the lungs.
The research was carried out by a team from the University of Auckland in New Zealand, and the results were published in the journal Circulation Research.
The researchers found that the lateral parafacial region is also connected to nerves that cause blood vessels to constrict, leading to increased blood pressure. In hypertensive conditions, this area becomes active, and when it was experimentally inactivated, blood pressure values returned to normal.
The results suggest that changes in breathing patterns, especially those involving strong contractions of the abdominal muscles, can trigger hypertension. Thus, identifying a type of abdominal breathing in hypertensive patients could indicate the cause and guide the treatment.
Another stage of the research analyzed whether this brain region can be influenced by medication. Direct administration of drugs that act on the brain is difficult because they do not selectively target a specific area.
The team later identified that the lateral parafacial region is activated by signals from outside the brain, from the carotid bodies—small structures located in the neck near the carotid artery that detect the level of oxygen in the blood. These structures can be safely targeted by drug treatment.
Researchers are currently testing a repurposed drug designed to reduce the activity of the carotid bodies and, indirectly, to inactivate this brain region without acting directly on the brain.
The discovery could lead to the development of new treatments for high blood pressure, particularly in patients with sleep apnea, in whom the carotid bodies are activated during episodes of stopping breathing during the night.