蛋白激酵素G(protein kinase G，PKG)是所有組織中一種非常重要的蛋白，在心血管系統中對調節血壓發揮重要作用。
沒有血管中產生的一氧化氮(Nitric oxide, NO)就無法完成這個過程。
UK scientists say they have discovered a new way to regulate blood pressure, offering hopes of new drugs to combat strokes and heart attacks.
One in four adults has high blood pressure and although powerful drugs are already available, few manage to achieve target blood pressure levels.
The pathway found in a study by King's College London involves a process called oxidation, reports Science.
Until now, oxidation has largely been linked with harm rather than good.
Indeed, free radicals and oxidants, such as hydrogen peroxide, can cause cell damage.
But they also play crucial roles in normal cell function.
Blood pressure control
Protein kinase G (PKG) is an important protein in all tissues, but in the cardiovascular system it plays a fundamental role in blood pressure regulation.
Nitric oxide produced within blood vessels is known to be crucial in this process.
But Joseph Burgoyne and colleagues at King's College have found a novel way in which the protein PKG can be regulated independently of nitric oxide.
They discovered that oxidants such as hydrogen peroxide cause a bond to form between two amino acids which, in turn, activates PKG. This then leads to a lowering of blood pressure.
Dr Philip Eaton, who led the King's team, said: "The research could lead to the development of drugs which activate this new pathway."
The researchers now plan to explore the role of this new pathway in the events leading to a heart attack.
Professor Jeremy Pearson, Associate Medical Director of the British Heart Foundation, which funded the research, said: "This research is exciting. Firstly, the team's novel discovery opens up opportunities for the design of new drugs to combat high blood pressure.
"Secondly, the mechanism provides new insights into how oxidant stress affects cells and tissues. Oxidant stress not only alters blood flow, but also affects the heart's ability to contract and is involved in a wide variety of inflammatory conditions."
Oxidation May Be New Blood Pressure RegulatorA novel way of regulating blood pressure has been discovered by British scientists. This breakthrough could lead to innovative drugs that fight heart attacks and stroke.
One quarter of UK adults suffer from hypertension (high blood pressure). Despite being treated with potent medication, many never manage to get their blood pressure levels back to normal.
Scientists at King's College London have found a pathway which involves oxidation. You can read about this in the journal Science.
Oxidation is a term we usually associate with free radicals and oxidants, which are harmful and cause cell damage. However, oxidation is central to normal cell function, say the scientists.
PKG (protein kinase G) plays a crucial part in regulating our blood pressure. We know that nitric oxide, which is produced inside our blood vessels, is a vital part of this process. The scientists, lead by Joseph Burgoyne, have discovered a new way PKG can be regulated without nitric oxide being involved.
Hydrogen peroxide, the scientists found, triggers a bond between two amino acids which activate PKG - resulting in lower blood pressure. They say this discovery could eventually lead to new drugs which activate this new pathway.
They would like to see what role this new pathway has in events that take place before the onset of a heart attack.
"Cysteine Redox Sensor in PKGI Enables Oxidant-Induced Activation"
Joseph R. Burgoyne, Melanie Madhani, Friederike Cuello, Rebecca L. Charles, Jonathan P. Brennan, Ewald Schröder, Darren D. Browning, Philip Eaton
Science DOI: 10.1126/science.1144318
Click here to view abstract online
Written by: Christian Nordqvist
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