The treatments potentially can become part of a therapeutic regimen for long-term care of hypertension and other cardiovascular ailments, said researchers at the Susan Samueli Center for Integrative Medicine at University of California, Irvine, in a paper published in the latest issue of Journal of Applied Physiology.

The electroacupuncture treatments provided temporary relief from the conditions that raise blood pressure during hypertensive states in tests on rats, the researchers found.

"This study suggests that acupuncture can be an excellent complement to other medical treatments, especially for those treating the cardiac system," said John C. Longhurst, lead investigator and director of the Samueli Center.

"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."

Acupuncture, the 3,000-year-old Chinese therapy, involves inserting needles at specific points on the body to help cure disease or relieve pain.

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.

In previous studies, Longhurst's team had identified at the cellular and molecular level how acupuncture excites brain cells to release neurotransmitters that either inhibit or heighten cardiovascular activity.

They had found that when an acupuncture needle is inserted at specific sites on the wrist, inside of the forearm or leg, it 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.

"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," Longhurst said. "Our goal is to help establish a standard of acupuncture treatment that can benefit everyone who has hypertension and other cardiac ailments."

(Xinhua News Agency March 29, 2005)