As the childhood saying goes, “he who smelt it, dealt it”, and we’re all familiar with that unpleasant whiff of rotten eggs, the ‘pleasant’ perfume released by breaking wind. This is the gas hydrogen sulphide at work.
But now a team of researchers has shown that this whiffy gas plays an important role in controlling blood pressure, and is produced by cells that line the blood vessels. The scientists found that hydrogen sulphide can relax blood vessels, dropping blood pressure.
To find the link, the researchers studied mice missing a gene for an enzyme called CSE, which has long been suspected to make hydrogen sulphide in the body. They measured the levels of the gas in the tissues of these mice, and compared them with normal mice, unsurprisingly finding that the mice lacking CSE had very little hydrogen sulphide.
Next, they used tiny blood-pressure cuffs on the mouse’s tails to measure their blood pressure, and found it was around 20% higher in the mice lacking CSE – showing they had serious hypertension. And they also found that blood vessels taken from the CSE-deficient mice hardly relaxed at all when they added a drug that normally relaxes them.
Although the work has only been done in mice so far, it’s highly likely that the same systems are at work in humans too. If this sounds familiar, it’s because we’ve known for some time about another gas produced by blood vessel cells, nitric oxide, that has a similar effect. Drugs that affect nitric oxide production are already in use – though one of them, Viagra, is rather more famous for its side effects.
Now this new hydrogen sulphide pathway has been discovered, it opens the door for the development of new types of treatment for high blood pressure.