Central regulation of blood pressure : role of angiotensin and nitric oxide

点击翻译按钮获取中文摘要

High blood pressure is a major public health problem in Western society with approximately 20% of adults affected. If left untreated serious damage to organs can occur and the risk of sudden cardiac death or stroke is greatly increased. While many factors contribute to the development of hypertension such as lifestyles, genes, diet, weight and exercise levels, a common feature in the early stages is an overactive nervous system in the kidney and in the heart which is most likely due to altered signals from the brain. A major question has been to understand why this occurs. One possibility is angiotensin (a hormone released from the kidney that is known to control body fluid) also acts in the brain to increase nerve activity to the kidney and heart and in this way contribute to high blood pressure. Our research has shown that normally brain angiotensin has relatively little activity but can be switched on by specific situations such as stress or a high salt. This may be by depleting anti-oxidants and producing an oxidative stress in the brain. With aging, stress, lack of exercise and other various environmental influences our body is less able to cope with oxidative stress which is the result of the normal cells function. The major thrust of this project is to determine whether the long term contribution of angiotensin in the brain to high blood pressure is caused by a high level of oxidative stress in the brain. We will see whether experimental animals still develop high blood pressure if angiotensin is blocked in the brain and see whether changing the oxidative stress levels in the brain affects this role. We will be able to better understand the interplay between these molecules in the brain which opens the way for the development of new highly specific drugs that can prevent the high level of nerve activity to the heart and kidney and hence the development of high blood pressure.