In experiments, activity in a brainstem region increased sympathetic signals and narrowed blood vessels. The findings are from animal models and have not established the same mechanism in people.
A study in rats has linked activity in a brain region involved in breathing control with a rise in blood pressure. The researchers examined the lateral parafacial region of the brainstem, which normally contributes to active exhalation during exercise, coughing or laughter.
In experiments reported in Circulation Research, activating neurons in the region increased sympathetic nervous-system activity, narrowed blood vessels and raised pressure in the animals. Inhibiting the same neurons in hypertensive rats brought their readings back toward normal.
The researchers suggest the mechanism could help explain an association between sleep apnoea and hypertension. Changes in oxygen and carbon-dioxide levels during pauses in breathing might activate the region, but this remains a proposed explanation rather than proof of a cause in humans.
The work was conducted in animals and does not establish a treatment or show that the same mechanism causes hypertension in people. The researchers say a next step is to find a way to influence the pathway without intervening directly in the brain.