Oxidants are good for the cardiovascular system

Scientists funded by the British Heart Foundation (BHF) have discovered that oxidants, which have historically been blamed for heart disease, have a vital role ensuring the heart pumps blood around the body effectively. The lead researchers, from the BHF Centre of Research Excellence at King's College London, now hope to develop drugs based on their discovery that could lower blood pressure and treat conditions caused by the heart not pumping properly, including certain forms of heart failure.

The study, published in Nature Communications, found that when the heart relaxes oxidants are released which activate an enzyme called Protein Kinase G (PKG), in a process called oxidation. The oxidation of PKG helps to ensure the amount of blood entering the heart is the same as the amount pumped out. This is vital in the functioning of a healthy heart.

When the researchers looked at the hearts of mice with a form of PKG that cannot be oxidised, they found that their hearts did not fill with blood properly and that their heart function was compromised. The findings in the heart were complemented by BHF-funded research on arteries published recently in Science Signaling. The researchers, led by BHF Research Fellow Dr Adam Greenstein from the University of Manchester, found activation of PKG by oxidants is also critical for the way arteries sense high blood pressure and then relax.

Looking at oxidants differently Dr Adam Greenstein, a BHF Research Fellow at the University of Manchester and an author on both papers, said: “Our research supports the really exciting concept that oxidants, traditionally viewed as ‘the bad guys of the cardiovascular system,’ are increasingly appreciated as integral to normal heart and arterial function.“This ties in with lots of misinformation about commercially available antioxidants and heart disease which takes focus off the real risk factors, such as weight, cholesterol, blood pressure and smoking.”
The scientists believe that dysregulation of the activation of PKG may occur in several cardiovascular diseases.