Research by scientists at UCL (University College London) has clearly demonstrated for the first time the structure and function of a gene crucial to the regulation of blood pressure. The discovery could be important in the search for new treatments for illnesses such as heart disease, the UKs biggest killer.
In a paper published online today in Nature Medicine, the team, led by Professor Patrick Vallance and Dr James Leiper, UCL Department of Medicine, reveal the role of the human gene dimethylarginine dimethylaminohydrolase (DDAH), showing that loss of DDAH activity disrupts nitric oxide (NO) production. NO is critical in the regulation of blood pressure, nervous system functions and the immune system.
The role of DDAH is to break down modified amino acids (Asymmetric dimethylarginine (ADMA) and monomethyl arginine (L-NMMA)) that are produced by the body and have been shown to inhibit NO synthase. These molecules accumulate in various disease states including diabetes, renal failure and pulmonary and systemic hypertension, and their concentration in plasma (the fluid component of blood) is strongly predicative of cardiovascular disease and death.
In a healthy human body, the majority of ADMA is eliminated through active metabolism by DDAH. Scientists have hypothesised that if DDAH function is impaired, NO production is reduced, and that this could be an important feature of increased cardiovascular risk.
To examine this pathway in more detail, the researchers deleted the DDAH gene in mice. These mice went on to develop hypertension, or high blood pressure. They also designed specific inhibitors (small molecules) which bind to the active site of human DDAH. These small molecule inhibitors also induced hypertension in mice, confirming the importance of DDAH in the regulation of blood pressure.
Dr Leiper, UCL Medicine, said: These genetic and chemical approaches to disrupt DDAH showed remarkably consistent resul
Contact: Ruth Metcalfe
University College London