Understanding why blood pressure control is different between the sexes

Sex-dependent regulation of vascular Kv7 channels (Mr Samuel Baldwin)

In the UK nearly one in seven men die from coronary heart disease, compared to one in twelve women. The reasons underlying this gender difference are not fully understood, but Professor Iain Greenwood’s team at St George’s are working to solve this puzzle. High blood pressure is a major risk factor for heart disease. Blood pressure is partly controlled by how much the muscle cells in the blood vessel walls contract, making the vessel narrower. More contraction of the muscle means narrower arteries, which means the heart has to pump harder to move blood around the body and puts greater strain on the heart. With BHF funding, this team has identified a protein on the surface of the muscle cells, called a Kv7 potassium channel, which helps to keep the muscle cells relaxed and therefore helps blood vessels to be more open. The team have discovered that, in arteries from male rats with high blood pressure, these channels get degraded, leading to the muscle cells being more contracted and the blood vessels being narrower. However, in female rats the Kv7 channels are less degraded and function more normally. The PhD student funded by this grant will work to unearth the reasons for this gender difference in blood pressure control, which could give new clues to help design new blood pressure medicines for both sexes.