October 24, 2008

Stinky Hydrogen Sulphide Linked To Blood Pressure

US researchers say the gas best known for being used in many stink bombs may also control blood pressure.

The foul odor of flatulence is due to small amounts of hydrogen sulphide - a toxic gas generated by bacteria living in the human gut.

But researchers say the gas is also produced by an enzyme in blood vessels that relaxes them and lowers blood pressure.

The Science journal reported that the findings in mice might lead to new treatments for high blood pressure.

The gas is produced in the cells lining blood vessels by an enzyme called CSE, said researchers at Johns Hopkins University, in Maryland.

Levels of hydrogen sulphide were almost depleted in mice engineered to be deficient in this enzyme, compared with levels in normal mice.

The mice deficient in CSE also had blood pressure measurements about 20% higher than the normal mice, comparable to serious hypertension in humans.

When the engineered mice were given the drug methacholine, which relaxes normal blood vessels, there was no difference, indicating the gas is responsible for the relaxation.

Nitric oxide, another gas, is already known to be involved in control of blood pressure.

"Now we know hydrogen sulphide'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," said researcher Dr. Solomon Snyder.

Professor Amrita Ahluwalia, an expert in vascular pharmacology at Barts and The London Medical School, said the study shows that smelly hydrogen sulphide is also likely to have a role in regulating blood pressure and it will be a bit of an impetus for scientists to develop more specific tools to work out what's going on.

"We know hydrogen sulphide is not good for us at high levels but it seems that at the lower levels in the body it is essential."

Treatments based on hydrogen sulphide could become important in a variety of cardiovascular diseases, according to Dr. Allan MacDonald, a reader in pharmacology at Glasgow Caledonian University.


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