Role Of Endothelial Vasodilator Mechanisms In Cardiovascular Control During Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$225,500.00
Summary
Cardiovascular diseases such as stroke and heart attack are the greatest killers in developed societies such as Australia. We now know that a number of metabolic disorders, and genetic and lifestyle factors, can increase the likelihood of individuals developing cardiovascular disease later in life, such as obesity, diabetes, and smoking. In many cases, individuals with these risk factors also have high blood pressure, which is a known cause of stroke and heart attack. This seems to be a particul ....Cardiovascular diseases such as stroke and heart attack are the greatest killers in developed societies such as Australia. We now know that a number of metabolic disorders, and genetic and lifestyle factors, can increase the likelihood of individuals developing cardiovascular disease later in life, such as obesity, diabetes, and smoking. In many cases, individuals with these risk factors also have high blood pressure, which is a known cause of stroke and heart attack. This seems to be a particular problem in patients with diabetes, a condition that currently affects around 150 million people worldwide. Indeed, almost 70% of patients that develop diabetes in later life, also develop high blood pressure. The aim of the studies outlined in this application is to increase our understanding of the way diabetes affects blood pressure. High blood pressure often accompanies established diabetes, but we have recent evidence that suggests that a gas (nitric oxide) made by the cells that line blood vessels (endothelial cells) and in nerve cells, protects the cardiovascular system from hypertension during the onset of diabetes. Our experiments will show whether the 'protective' nitric oxide comes from nerves or the endothelial cells, and how it affects various blood pressure control mechanisms in diabetes. Our experiments will also show whether this protective action of nitric oxide is eventually lost as the organ damage that occurs in diabetes proceeds. This information should help in the design of new drug treatments and other therapies aimed at reducing the occurrence of high blood pressure, and hence cardiovascular disease, in diabetes.Read moreRead less
RENAL VASCULAR HYPERTROPHY AND REMODELLING IN SHR: SYMPATHETIC NERVOUS SYSTEM AND IMPLICATIONS FOR HYPERTENSION
Funder
National Health and Medical Research Council
Funding Amount
$191,561.00
Summary
High blood pressure (hypertension) remains a major health problem for Australians. One in six Australians suffer from hypertension, with consequent increased risk of stroke and heart attack. Anti-hypertensive treatments are available, but must usually be taken for the rest of the patient's life and the cost to the taxpayer of anti-hypertensive drugs is greater than for any other health problem. Prevention of high blood pressure depends on identifying the initial cause - but we still do not know ....High blood pressure (hypertension) remains a major health problem for Australians. One in six Australians suffer from hypertension, with consequent increased risk of stroke and heart attack. Anti-hypertensive treatments are available, but must usually be taken for the rest of the patient's life and the cost to the taxpayer of anti-hypertensive drugs is greater than for any other health problem. Prevention of high blood pressure depends on identifying the initial cause - but we still do not know the cause in over 90% of hypertensive people. This project will study whether overactivity of the nerves to the blood vessels of the kidney might be the cause. There is evidence for this in humans, and in a strain of rats which develops high blood pressure (the spontaneously hypertensive rat). Our experiments will study these rats to see whether nerves affect the structure and function of the blood vessels of the kidney in ways that lead to increased blood pressure.Read moreRead less
The Role Of Coronary Artery Baroreceptors In Cardiopulmonary Reflexes
Funder
National Health and Medical Research Council
Funding Amount
$361,018.00
Summary
The blood vessels and heart contain sensors that report on the state of the circulation to the brain. Blood vessel sensors send information about the level of blood pressure to the brain, and the brain coordinates appropriate changes in the activity of the heart and blood vessels so that blood pressure stays within narrow limits and blood flow to the brain is protected. Heart sensors send information to the brain about pressures in the heart and the release of chemicals during heart pain. Specia ....The blood vessels and heart contain sensors that report on the state of the circulation to the brain. Blood vessel sensors send information about the level of blood pressure to the brain, and the brain coordinates appropriate changes in the activity of the heart and blood vessels so that blood pressure stays within narrow limits and blood flow to the brain is protected. Heart sensors send information to the brain about pressures in the heart and the release of chemicals during heart pain. Specialized pressure receptors, like the receptors on blood vessels, have recently been reported to exist on the main blood vessels in the heart and, although not extensively studied, likely send information to the brain to participate in blood pressure regulation and to protect the supply of blood to the heart. These heart receptors normally work in concert with, and overshadowed by, the blood vessel receptors. In cardiovascular disease this concerted and complimentary interaction may be lost, resulting in contradictory signals being sent to the brain and inappropriate regulatory responses occurring. To study the functions of these heart receptors we will compare the number and types of nerves going to the heart receptors with the nerves that go to the blood vessel receptors to tell us whether their functions are likely to be similar. We will activate the heart receptors in healthy conscious animals to see what happens to blood pressure, heart rate, breathing patterns and blood flow to different organs. Finally we will use brain mapping techniques to see which brain cells are excited when the heart receptors are excited, and brain cell recording techniques to determine how individual brain cells respond to heart or vessel information. These studies will provide important new information about heart sensors, and help us understand the role these sensors have in heart disease or heart attack. This knowledge will aid the development of effective new ways of treating heart disease.Read moreRead less