July 23, 2007

(SACRAMENTO, Calif.) — The Western States Affiliate of the American Heart Association  has awarded an $81,000 grant to UC Davis postdoctoral fellow Andrea Bechtold, supporting her for two years as she conducts research into the immediate benefits of exercise for those with high blood pressure.

“We know a lot about what happens to the hearts of people with hypertension after they exercise, but there really is little known about what happens in the brain — the place where blood pressure is controlled,” said Bechtold, a researcher in the laboratory of Ann Bonham, professor of pharmacology and Executive Associate Dean at UC Davis Health System.

Bechtold, one of 51 young investigators to be chosen, received the highest rank by a panel of experts in cardiovascular research, said Annie Oliveto, director of research administration for the Western States Affiliate.

“We are excited about funding innovative and exciting research, as well as helping young investigators, like Bechtold, become established leaders in cardiovascular research,” she said.

AHA's Western States Affiliate includes California, Nevada and Utah. The affiliate received 215 applications for this award. The AHA, a non-profit organization, is the largest private funding source for cardiovascular research in the U.S.

The AHA has long recommended daily exercise for those with high blood pressure, or hypertension — a major risk factor for the development of heart disease. Exercise, it turns out, immediately lowers blood pressure — an effect than can last up to a day, Bechtold said.

“We are looking at what happens in the brain to cause this post-exercise decrease in people with high blood pressure,” Bechtold said.

Basic regulation of blood pressure is controlled in the brainstem via the baroreflex, a feedback loop in which blood pressure is increased or decreased in response to signals received from peripheral nerves. The area of the brainstem involved in this reflex is called the NTS, an acronym for the Latin translation of “nucleus of the solitary tract.”

Bonham's previous research showed that post-exercise decreases in blood pressure involved Substance P, a chemical which acts as both a neurotransmitter and a neuromodulator. If the receptors for Substance P in the NTS were blocked, blood pressure was not lowered significantly after exercise.

Bonham's group is working to better understand the baroreflex pathway by looking at how Substance P affects other neurotransmitters. Bechtold's research focuses on the interaction between Substance P and GABA (gamma-aminobutyric acid), the major inhibitory neurotransmitter in the brain. She is looking at how activation of GABA receptors results in changes in blood pressure and heart rate before and after exercise.

“Understanding how exercise lowers blood pressure in people with hypertension will hopefully give patients the information they need to commit to regular exercise,” Bechtold said. This research could also help develop new drugs for those who need them, she said.