Emory scientists find oral tetrahydrobiopterin can reduce high blood pressure

ORLANDO - According to the American Heart Association (AHA), one in four U.S. adults has hypertension (HTN). Without adequate treatment, HTN can lead to stroke, heart attack, heart failure or kidney failure. In a presentation at the AHA's Scientific Sessions here today, Sonya Lefever, MD, a senior cardiology fellow at Emory, discussed findings by Emory researchers suggesting that oral tetrahydrobiopterin ( also known as BH4) holds promise as a therapy for patients with HTN.

BH4 is an essential co-factor needed in the body for the synthesis of nitric oxide (NOS). "In its absence, the nitric oxide synthases become 'uncoupled', producing superoxide rather than nitric oxide and this appears to play a role in the development of HTN. We've also found that when oxidation of BH4 occurs in mice with salt sensitive hypertension, there is a further increase in blood pressure," says Dr. Lefever. "When we gave the animals oral BH4 treatment, these abnormalities were corrected and blood pressure was reduced. We decided to see if BH4 would also improve endothelial dysfunction and lower BP in humans with hypertension -- and we found just those results."

Eight patients with poorly controlled HTN who were on traditional antihypertensive therapy were treated with oral BH4 for eight weeks. "Blood pressure reduction was significant after three weeks of this therapy," Dr. Lefever notes. "While this is a small study and more research needs to be done, it does appear that BH4 can lower blood pressure in patients with HTN, an effect that is likely secondary to increased availability of nitric oxide and enhanced vasodilation. "

The Emory Heart Center is comprised of all cardiac services and research at Emory University Hospital, Emory Crawford Long Hospital) Carlyle Fraser Heart Center, the Andreas Gruentzig Cardiovascular Center of Emory University and the Emory Clinic. Ranked among the nation's top ten heart centers by U.S. News & World Report's annual survey, the Emory Heart Center has a rich history of excellence in all areas of cardiology and cardiac surgery -- including education, research and patient care. It is internationally recognized as one of the birthplaces of modern interventional cardiology and was the site of the first coronary stent implantation in the United States, the only single site randomized comparison of angioplasty and bypass surgery and pioneering work in vascular brachytherapy.

Media Contacts: Sherry Baker, 404/377-1398, emoryheartnews@aol.com
Kathi Baker, 404/727-9371, kobaker@emory.edu
Janet Christenbury, 404/727-8599, jmchris@emory.edu

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