Newswise — An international research team, with scientists from the University of Saskatchewan, has discovered that a gas produced in blood vessels regulates and lowers blood pressure.

The team's findings, based on research in mice, may one day be used to design drug therapies for controlling high blood pressure in humans.

In a study published today in Science, the U of S research team and colleagues from Lakehead University and Johns Hopkins University found that hydrogen sulfide (H2S), commonly known as the gas with a 'rotten egg' smell, can regulate blood pressure levels by relaxing blood vessels.

"This groundbreaking work is the result of five years of intensive research that began at the U of S," says U of S pharmacologist Dr. Lingyun (Lily) Wu, a corresponding author on the paper.

Based on a study conducted in 2001 by former U of S physiology professor Dr. Rui Wang, the team of scientists suspected that H2S could play a role in blood pressure regulation. The U of S was the first to find where H2S is produced in the cardiovascular system.

Building on the foundation laid by this preliminary research, Dr. Wu and her team worked with Dr. Wang to genetically alter lab mice by removing the enzyme responsible for regulating H2S.

The scientists discovered that the altered mice, which had lower than normal levels of H2S, experienced 15 to 20 per cent increases in blood pressure, similar to hypertension in humans.

"Establishing at the U of S a mouse colony that lacks a specific enzyme made this discovery possible," says Dr. Wu.

Though the study was conducted on mice, it could prove to be an important finding for human health.

"Now that we know hydrogen sulfide's role in regulating blood pressure, it may be possible to design drug therapies that enhance its formation as an alternative to the current methods of treatment for hypertension," says Johns Hopkins neuroscientist Dr. Solomon Snyder, a corresponding author of the paper.

As a molecular messenger, or gasotransmitter, H2S functions in a similar way to chemical signals such as nitric oxide, dopamine, and acetylcholine, which transmit signals between nerve cells and stimulate or slow down mind-brain activities.

"It's difficult to overestimate the biological importance of hydrogen sulfide or its implications in hypertension as well as diabetes and neurodegenerative diseases," says Dr. Wang, now vice-president of research at Lakehead University. "Most human diseases probably have something to do with gasotransmitters."

To date, only two other gaseous molecules in the body have been found to modulate physiological functions. One is nitric oxide, which was also found to relax blood vessels, the discovery of which led to a Nobel Prize.

This research project was supported by grants from the Canadian Institutes of Health Research and the U.S. Public Health Service. Dr. Wu is also funded by the Heart and Stroke Foundation of Saskatchewan. She has published more than 80 peer-reviewed papers on insulin resistance, hypertension management, and gasotransmitter research.

Authors on the paper are Guangdong Yang, Lingyun Wu, Bo Jiang, Wei Yang, Jiansong Qi, Kun Cao, Qing Meng, all of the U of S; Rui Wang and Shengming Zhang of Lakehead University; and Asif K. Mustafa, Weitong Mu and Solomon Snyder, all of Johns Hopkins University.

For the full paper, visit http://www.sciencemag.org/cgi/content/full/322/5901/501iAbout U of S (www.usask.ca): The University of Saskatchewan is one of the leading medical doctoral universities in Canada. With 58 degrees, diplomas and certificates in over 100 areas of study, the university is uniquely positioned in the areas of human, animal and plant studies. World-class research facilities, renowned faculty and award-winning students make the U of S a leader in post-secondary education.