U.S. researchers have identified a drug compound that dramatically lowers blood pressure, improves heart function and prevents damage to the heart and kidneys in rats with persistent hypertension.

The findings, which appear Friday in the latest edition of the journal Hypertension, could lead to a new class of antihypertensive drugs designed to address two major problems associated with cardiovascular disease: high blood pressure and the tissue damage associated with it, known as fibrosis.

"When people have heart attacks (or suffer from hypertension) the blood vessels get more rigid," said study author David Ostrov from University of Florida. "We discovered a compound that reverses the fibrosis that makes the blood vessels more rigid."

Angiotensin-converting enzyme (ACE) plays a key role in the development of high blood pressure. It produces angiotensin II, a potent hormone that constricts blood vessels and causes blood pressure to rise. So patients with hypertension and cardiovascular disease usually take ACE inhibitors. But these drugs have limited capacity to repair heart function and to reverse tissue damage.

In contrast, another enzyme -- ACE2, not only lowers levels of angiotensin II but also converts it to a hormone that helps protect the cardiovascular system.

Therefore, researchers used supercomputers to process 140,000 prospective drug compounds. They finally succeeded in identifying an ideal compound that enhances the ACE2 enzyme's activity.

They have tested the compound in hypertensive rats that had developed fibrosis of the heart and kidney. The animals received the drug for two weeks. Tissue samples from treated animals revealed a significant decrease in fibrosis of the heart, kidney and blood vessels. Additional research will continue to explore the compound's effectiveness in animals and humans.

(Xinhua News Agency May 3, 2008)