In this study, the Longhurst team applied acupuncture to specific points on the forelimb of test rats with artificially elevated blood pressure rates; these same sites on humans are on the inside of the forearm slightly above the wrist. The researchers found that acupuncture alone had no effect on blood pressure.
Next, they added electrical stimulation to the acupuncture treatment by running an electrical current through the needles. High frequencies of stimulation also had no effect, but low frequencies lowered increased blood pressure by as much as 40 to 50 percent. Overall, the researchers found that a 30-minute treatment reduced blood pressure rates in these test rats by 25 mmHg -- with the effect lasting almost two hours.
"This type of electroacupuncture is only effective on elevated blood pressure levels, such as those present in hypertension, and the treatment has no impact on standing blood pressure rates," said Longhurst, a cardiologist who is also the Lawrence K. Dodge Professor in Integrative Biology. "Our goal is to help establish a standard of acupuncture treatment that can benefit everyone who has hypertension and other cardiac ailments."
Longhurst and his colleagues currently are testing this electroacupuncture treatment method in an ongoing human study.