Scientists Pinpoint Role of Heart Disease Genes

June 19, 2002

LONDON (Reuters) - Canadian scientists have identified the roles of two genes that play a vital part in heart disease and which could lead to better treatments for the illness that is a number one killer in many countries.

In research reported in the science journal Nature on Wednesday, Professor Josef Penninger of the University of Toronto said one of the genes contributes to heart failure and the other protects against it.

When both of the genes, angiotensin converting enzyme (ACE) 1 and 2, are balanced in mice, the animals developed healthy hearts.

In studies using genetically modified mice, Penninger and Dr. Peter Backx, of the University Health Network in Toronto, discovered that mice with ACE 1 but not the ACE 2 gene developed cardiovascular disease.

"This finding is really amazing because it opens up new avenues for the treatment of cardiovascular diseases and heart failure," Penninger said in a statement.

ACE 1 has been shown to help maintain normal blood pressure by producing hormones that cause blood vessels to constrict. The Canadian researchers have now shown that if the by-products of ACE 1 are not controlled they can contribute to the development of heart disease.

"This is the first time that scientists have been able to show that the ACE 1 enzyme is a critical contributor to the inability of the heart to function optimally," Penninger explained.

"Perhaps even more important, we've also shown that the ACE 2 gene plays a highly protective role in heart function by counteracting the negative effects of ACE 1 by-products," he added.

The findings also explained how blood pressure drugs known as ACE inhibitors work and may offer clues about how to increase their effectiveness and to overcome unwanted side effects.

"Up to now, nobody knew how this system worked," said Backx.

"But if we understand the connection between peptides and ACE inhibitors, we can begin to tailor the drugs to be much more specific," he added.

Although the research was done on animals, the scientists said the genes play a similar role in humans.

Hypertension, or high blood pressure, can cause heart attacks, stroke and heart failure.