Professor Roger A.L. Dampney

Professor Dampney has been awarded the Dorothy Frances Martin Research Award. It is the third award he has received from the National Heart Foundation. Professor Dampney's research is concerned with the function of a particular type of receptor in the brain in regulating blood pressure. Basic life functions, such as breathing, the heart beat and simple reflexes, are controlled by the medulla oblongata in the brain stem, which has been found to contain large numbers of a kind of receptor known as angiotensin type 1 (AT1). However we also know that a whole range of external stimuli will affect heart rate. Pathways in the brain that are involved in triggering cardiovascular responses to external stimuli are poorly understood. We do know that the hypothalamus is a key centre, and that there is a nerve pathway from this hypothalmus down to a key centre in the medulla that regulates blood pressure. The important discovery that Dr Tatsuya Tagawa made in this laboratory is that this descending pathway from the hypothalamus activates nerve cells in the medulla via AT1 receptor. We have known for 10 years that these receptors existed in the medulla, but we didn't know what they did. His study suggests a role for them, that they mediate inputs from higher levels of the brain. In conditions like heart failure , and in some kinds of high blood pressure, there is a greatly increased level of firing of sympathetic nerves that control the heart and blood vessels. It is possible that one of the factors that generates this increased activity is increased firing of certain regions of the brain, particularly the hypothalamus, which influences what happens in the medulla, and these critical nerve cells in the medulla then in turn affect blood pressure and heart rate. The AT1 receptors may mediate these effects. As there are drugs already available which specifically block these receptors, it should be possible to modify the effects of the hypothalamus on the sympathetic activity, which could be of benefit in the treatment of heart failure and high blood pressure. The work is being carried out by principally by Dr Marco Fontes with co-investigators, Associate Professor Pilowsky and Dr Goodchild from the Department's Hypertension and Stroke Research Laboratory at Royal North Shore Hospital.