In tests on rats, the researchers found that electroacupuncture treatments provided temporary relief from the conditions that raise blood pressure during hypertensive states. Such treatments, they believe, potentially can become part of a therapeutic regimen for long-term care of hypertension and other cardiovascular ailments in people.
"This study suggests that acupuncture can be an excellent complement to other medical treatments, especially for those treating the cardiac system," said Dr. John C. Longhurst, director of the Samueli Center and study leader. "The Western world is waiting for a clear scientific basis for using acupuncture, and we hope that this research ultimately will lead to the integration of ancient healing practices into modern medical treatment."
The study appears in the March issue of the Journal of Applied Physiology.
Acupuncture is a 3,000-year-old form of Chinese medicine that involves inserting needles at specific points on the body to help cure disease or relieve pain. In previous studies, Longhurst and his UCI colleagues have identified at the cellular and molecular level how acupuncture excites brain cells to release neurotransmitters that either inhibit or heighten cardiovascular activity.
They have found that when an acupuncture needle is inserted at specific sites on the wrist, inside of the forearm or leg, this triggers the release of opioid chemicals in the brain that reduce excitatory responses in the cardiovascular system. This decreases the heart's activity and its need for oxygen, which in turn can lower blood pressure, and promotes healing for a number of cardiac ailments, such as myocardial ischemia (insufficient blood flow to the heart) and hypertension.
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.
Drs. Wei Zhou, Liang-Wu Fu, Stephanie C. Tjen-A-Looi and Peng Li of the UCI Department of Medicine participated in the study, which was funded by the National Heart, Lung and Blood Institute, and the Larry K. Dodge Endowed Chair.
The Susan Samueli Center for Integrative Medicine in the UCI School of Medicine is focused on scientific research and education in the broad field of complementary and alternative medicine. The center, which was established in early 2000 through a gift from Henry and Susan Samueli, is dedicated to public and professional education and scientific research on the use of complementary and integrative approaches in wellness and prevention as well as health care. For more information, see: www.ucihs.uci.edu/com/samueli.
About the University of California, Irvine: The University of California, Irvine is a top-ranked public university dedicated to research, scholarship and community service. Founded in 1965, UCI is among the fastest-growing University of California campuses, with more than 24,000 undergraduate and graduate students and about 1,400 faculty members. The second-largest employer in dynamic Orange County, UCI contributes an annual economic impact of $3 billion.
UCI maintains an online directory of faculty available as experts to the media. To access, visit www.today.uci.edu/experts.