Hundreds of thousands of deaths every year can be traced back to hypertension, better known simply as high blood pressure. This condition plays a role in such diseases as heart attack, kidney disease and stroke. Now a team of scientists led by the University of Edinburgh discovered that a particular kind of immune system cells could be holding the key to tackling high blood pressure.
Macrophage's role is to collect harmful particles, bacteria and cancer cells, but it is probably also regulating blood pressure. Image credit: NIAID via Wikimedia (CC BY 2.0)
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Macrophages are central to the body’s immune system. Their role is to engulf and digest cellular debris, foreign substances, microbes, cancer cells and other potentially harmful particulates. Macrophages are specialized – different types of macrophages work in different media in the body where microbial invasion or accumulation of foreign particles is likely.
Now scientists discovered that macrophages also scavenge for and break down molecules of a powerful hormone known as endothelin. This means that macrophages are actively regulating levels of endothelin, which helps blood vessels relax and regulate blood pressure. In other words, scientists have just discovered a role of macrophages that was previously unknown.
Essentially what it means is that lower levels of macrophages could result in a higher blood pressure. Scientists already have so empirical data to support such hypothesis. Experiments with mice showed that reduced levels of macrophages result in a higher blood pressure. Interestingly, scientists managed to reduce the number of macrophages simply by administering a diet with high concentrations of salt.
Taking the salt away again allowed the macrophage level to return to normal and blood pressure also normalized. Experiments with genetically modified mice that were lacking endothelin as well as with mice with artificially reduced blood pressure revealed the same thing – macrophages are participating in regulating blood pressure.
These findings should help identifying people who are at most risk of developing problems relating to hypertension. And, of course, this research could lead to new improved therapies fighting hypertension.
Professor Matthew Bailey, one of the researchers in this study, said: “Hypertension affects millions of people across the globe, including 70 per cent of people over 70. Our discovery sheds light on risk factors, and crucially, opens routes to investigate new drugs that could help patients. Our next steps will be to investigate the role of macrophages in people living with hypertension”.
Hypertension literally affects millions in the entire world and doctors quite often struggle to find the cause to this condition. Now it looks like immune system can explain at least part of these cases.
Source: University of Edinburgh