Nerves a key to high blood pressure
Helping doctors to identify which patients are more at risk of cardiovascular disease and stroke is at the heart of
research being carried out by Dr Carolyn Barrett, the latest researcher to win a prestigious Sir Charles Hercus Health
Research Fellowship, awarded by the Health Research Council of New Zealand.
Dr Barrett, who is based in the Department of Physiology at the University of Auckland, hopes to understand the link
between the unconscious bodily functions
linked to the central nervous system, commonly known as the ‘fight or flight’ response, and the development of high
blood pressure. This would mean that clinicians will have a better idea of which patients are likely to be at risk.
Dr Barrett believes that renal sympathetic nerve activity, commonly caused by stress, may be a precursor to an increase
in blood pressure.
“You typically hear about people who are stressed and a stressed person tends to have an increase in sympathetic nerve
activity, causing a constriction of the blood vessels, so that may be one mechanism of how a stressful job could cause
an increase in blood pressure.”
“We know that in humans there is an increase in sympathetic nerve activity in people with a family background of
hypertension, and also in borderline hypertensive people,” she says.
“But there doesn’t seem to be such convincing evidence that there’s an increase in sympathetic nerve activity in people
who have long-term, established hypertension. That tends to suggest that the increase in sympathetic activity is
involved in the development of hypertension in the first place and there’s pretty good evidence that it’s specifically
activity to the kidney that produces increases in hypertension.”
Dr Barrett’s Hercus Fellowship project will be in two parts - the first further investigating what’s specific about
renal sympathetic nerve activity. The second part of the project will involve trying to translate that to people and see
how a change in renal sympathetic activity can be measured in them, says Dr Barrett.
“We know that we can’t directly measure renal sympathetic activity in humans but there are a number of measures that we
can use, such as recording muscle sympathetic activity.”
Being able to reliably predict renal sympathetic nerve activity may provide them with a marker that is more accurate and
less flawed, and much better for use in the clinical setting.
Established to build New Zealand’s future capability in world-class research, the Sir Charles Hercus Health Research
Fellowship, valued at $0.5M over four years, is designed to support outstanding post-doctoral scientists establish
careers as independent health researchers. The scheme has proved an effective incentive and mechanism for retaining some
of our most promising talent in New Zealand.
The Sir Charles Hercus Health Research Fellowship was named in recognition of the contributions that Sir Charles Hercus
(1888-1971) made to biomedical, clinical, and public health research during a distinguished 36-year career at the
University of Otago, and his dedicated service to the Medical Research Council.
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