Averting the harmful effects of high blood pressure

A novel role for B type natriuretic peptide (BNP) and phosphodiesterase 2 in cardiac sympathetic neurons during development of hypertension

High blood pressure, or hypertension – is a risk factor for heart and circulatory disease. Research to understand how high blood pressure is controlled and what goes wrong in disease could reveal ways to prevent the harmful effects of high blood pressure. When blood pressure is high, the nervous system releases a chemical called noradrenaline. Noradrenaline is known as the ‘fight or flight’ hormone, and its role is to increase the amount of oxygen going to the brain and the body so it can deal with a stressful situation. But noradrenaline speeds up the heart and further increases blood pressure, so this adds to the already harmful effects of high blood pressure. In healthy hearts, a molecule called B type natriuretic peptide (BNP) that is released with each beat of the heart can tell the nerves not to release too much noradrenaline. But in diseased hearts or in high blood pressure BNP does not work. With BHF funding, Professor David Paterson and his team at the University of Oxford have found a fault in an enzyme in a nerve cell, called phosphodiesterase 2 in high blood pressure, which may explain why BNP can no longer control the amount of noradrenaline released. The BHF has awarded them a further grant to see if they can, in rats, re-establish the protective action in diseased nerves that supply the heart. They will work out which molecules interact with phosphodiesterase 2 and if these interactions are different in nerve tissue.