Early Events In Arteriolar Remodeling: Adaptation To Prolonged Vasoconstriction
Funder
National Health and Medical Research Council
Funding Amount
$415,750.00
Summary
Small arteries, while acutely responding to their environment with changes in diameter to regulate local blood flow and pressure, also undergo structural adaptation or remodelling. These events occur over a range of time-frames and involve both non-genetically and genetically regulated events. Thus a contractile event, while initially decreasing vessel diameter, also activates longer time frame processes which can span from rearrangment of cellular junctions-contacts to overt structural changes ....Small arteries, while acutely responding to their environment with changes in diameter to regulate local blood flow and pressure, also undergo structural adaptation or remodelling. These events occur over a range of time-frames and involve both non-genetically and genetically regulated events. Thus a contractile event, while initially decreasing vessel diameter, also activates longer time frame processes which can span from rearrangment of cellular junctions-contacts to overt structural changes within the vessel wall (for example thickening of the muscle layer). These adaptive processes may enable the forces of contraction to be maintained without continued energy expenditure and damage to the vessel per se. However, they can also contribute to long-term alterations in the control of blood pressure and perhaps contribute to states of hypertension as well as other common vascular diseases. For these studies we will use arterioles, isolated by microsurgical techniques, together with sophisticated computer and video-based approaches. These techniques allow arterioles to be studied under controlled conditions and relevant biochemical measurements performed. We will also use a cell model where cultured cells will be studied after defined periods of mechanical stimulation (for example stretch). Cells will be probed using a novel microscopic technique (atomic force microscopy) which enables the cell membrane to be studied with respect to changes in composition as well as physical characteristics (for example stiffness). The studies are relevant to our understanding of the normal adaptive processes occurring within blood vessels to control blood flow and pressure. The studies are also of direct relevance to our understanding of common vascular disease states including hypertension, complications of diabetes and chronic inflammatory disorders.Read moreRead less
How Does Activated Protein C Create Intact, Non-leaky, Stable Blood Vessels?
Funder
National Health and Medical Research Council
Funding Amount
$564,644.00
Summary
Vascular dysfunction is a common feature of many diseases, including sepsis, diabetes, atherosclerosis, tumours and asthma. These vessels have compromised structural and functional integrity, leading to leakage of blood components and causing inflammation in tissues. Based on our recent findings, this project aims to discover how activated protein C creates normal, healthy non-leaky blood vessels and prevents vascular dysfunction in disease.
Local Microvascular Regulatory Mechanisms In Diabetes: Relevance To Neuropathy
Funder
National Health and Medical Research Council
Funding Amount
$212,036.00
Summary
In diabetes mellitus, the excessive levels of sugar in the blood may cause changes in metabolic processes within cells that lead to disturbances in the function of the circulatory and nervous systems. Such disturbances have been shown to occur in the early stages of diabetes and ultimately lead to longterm consequences including poor wound healing (often culminating in limb amputations), increased risk of blindness, kidney disease and heart failure. At present it is not possible to restore norma ....In diabetes mellitus, the excessive levels of sugar in the blood may cause changes in metabolic processes within cells that lead to disturbances in the function of the circulatory and nervous systems. Such disturbances have been shown to occur in the early stages of diabetes and ultimately lead to longterm consequences including poor wound healing (often culminating in limb amputations), increased risk of blindness, kidney disease and heart failure. At present it is not possible to restore normal metabolism, leaving patients at risk of developing complications involving the circulatory and nervous systems. An understanding of the processes involved in the development of such complications would allow alternate treatment strategies to be devised in order to improve the quality of life and life expectancy of diabetic patients. The events leading to abnormalities in the function of the circulatory and nervous systems are uncertain, however, studies have demonstrated that in diabetes there may be an insufficient blood supply to nerves and this would be expected to cause nerve damage. At present, our understanding of the factors involved in regulating blood flow to nerves is limited. The studies described in this proposal are aimed at testing the hypothesis that nerve blood vessels are themselves involved in the regulation of flow through an intrinsic ability to change their diameter in response to tissue demands and that in diabetes alterations in the capacity of nerve blood vessels to constrict or dilate compromises their role in the control of nerve blood flow . Information obtained from these studies will improve our understanding of the early disturbances in the function of circulatory and nervous systems leading to alterations in blood flow which precede the development of overt changes characteristic of the complications associated with diabetes. This will provide insight into developing new treatment strategies for diabetic patients.Read moreRead less
Antioxidant Glutathione Peroxidase (GPx) Mimetics And Atherosclerosis: A Role For Targeted Antioxidant Therapy.
Funder
National Health and Medical Research Council
Funding Amount
$358,319.00
Summary
This proposal investigates the use of antioxidant therapy, targeted at increasing the function of the body's important antioxidant enzyme GPx1, to reduce atherosclerosis both in a non-diabetic and diabetic setting. Strong clinical evidence and our recently published data support an important role for GPx1 in limiting atherosclerosis. We will now investigate the molecular mechanisms involved in mediating these effects and whether compounds that mimic GPx1 function reduce atherosclerosis.