Cortictropin Releasing Factor As A Therapeutic Target For Alcohol And Drug Abuse
Funder
National Health and Medical Research Council
Funding Amount
$504,097.00
Summary
A key problem with alcoholism, as with addiction generally, is the chronically relapsing nature of the disorder. This can be modelled in rodents and there is good general correspondence between animal studies of reinstatement and human experience of relapse. We have identified brain chemicals involved in this process. Consequently, by better understanding the biological mechanisms related to addiction and relapse, we will be in a position to counter this devastating condition.
Role Of GAT-1 Transporter Channels In Opioid Dependence
Funder
National Health and Medical Research Council
Funding Amount
$524,456.00
Summary
Opioid drugs including heroin and morphine are very addictive. After cessation of chronic use of these drugs an intensely unpleasant withdrawal syndrome develops that contributes to relapse. Brain mechanisms that produce withdrawal are still poorly understood. The present work will determine the pathological cellular and molecular mechanisms that produce withdrawal in inhibitory brain nerve cells known to be involved in generating withdrawal discomfort and relapse to compulsive drug use.
Novel Delta Receptor Expression In Opioid Tolerant/dependent Neurons
Funder
National Health and Medical Research Council
Funding Amount
$370,350.00
Summary
Opioids such as morphine and heroin act on specific molecular targets, or receptors, in the brain. Long term use of opioids produce changes in brain receptor systems that greatly diminish the effects of these drugs (tolerance), as well as producing an adverse withdrawal syndrome on cessation of use (physical dependence). The present proposal will identify the mechanisms of adaptations in cellular function in nerve cells critical for these changes. In particular, we have identified enhanced sensi ....Opioids such as morphine and heroin act on specific molecular targets, or receptors, in the brain. Long term use of opioids produce changes in brain receptor systems that greatly diminish the effects of these drugs (tolerance), as well as producing an adverse withdrawal syndrome on cessation of use (physical dependence). The present proposal will identify the mechanisms of adaptations in cellular function in nerve cells critical for these changes. In particular, we have identified enhanced sensitivity of receptor, the delta receptor, that is closely related to the opioid receptor but is not a target for heroin or morphine. We will identify the mechanisms of enhanced activity of this receptor after chronic use of morphine with a view to tergeting therapeutics to manage tolerance and physical dependence in opioid addicts and chronic pain patients.Read moreRead less
Clozapine Toxicity: Role Of Pharmacogenetic Variation In CYP Enzymes And Bioactivation Mechanisms In Patient Neutrophils
Funder
National Health and Medical Research Council
Funding Amount
$336,000.00
Summary
The treatment of mental disorders such as schizophrenia involves the administration of potent drug combinations to patients. Some individuals, however, do not respond to commonly-used antipsychotic drugs and their condition only improves with a unique drug called clozapine. The major problem with clozapine is its toxicity toward blood cells, heart and other organs. All people who receive clozapine must be monitored closely, especially in the first 3-4 months after starting therapy. Several new d ....The treatment of mental disorders such as schizophrenia involves the administration of potent drug combinations to patients. Some individuals, however, do not respond to commonly-used antipsychotic drugs and their condition only improves with a unique drug called clozapine. The major problem with clozapine is its toxicity toward blood cells, heart and other organs. All people who receive clozapine must be monitored closely, especially in the first 3-4 months after starting therapy. Several new drugs have been suggested to be safer versions of clozapine but these are all ineffective. Clozapine is the only agent that is effective in people who do not respond to the other drugs used to treat schizophrenia. Thus, clozapine toxicity, which necessitates discontinuation of the drug, is a devastating outcome because there is no alternative treatment that is available. Another significant problem with clozapine is that its rate of removal from the body is slowed down by many other drugs that are used concurrently. The problems with clozapine occur in some but not all individuals. This suggests that the patient's genetic makeup and their exposure to drugs and environmental agents determine the incidence of toxicity. The present project looks at how clozapine is removed from the body and how it is converted into a toxic product that damages cells. These processes will be examined, with emphasis on differences between individual patients, and strategies to protect cells from damage from the toxic derivative will be tested. Corresponding studies will be done in patients who are receiving clozapine as treatment for psychoses. We will be able to compare experimental and clinical findings in order to identify those patients who appear to be at risk. This will be possible before the toxic effects occur and will help us to identify subjects in whom the drug should only be used with great care. We may also devise strategies that will minimise the incidence of toxicity.Read moreRead less
Human Arylamine N-acetyltransferase Regulation And Function - Effect Of Genetic Poymorphisms.
Funder
National Health and Medical Research Council
Funding Amount
$421,980.00
Summary
How we handle chemicals that enter our bodies depends on a series of enzymes that are responsible for breaking down the chemicals and eliminating them. The activity of many of these enzymes varies between individuals so our responses to chemicals and drugs is different for each individual. Some of the enzymes vary because of inherited mutations, but others vary because of the diets we eat and the environment in which we live. This project will investigate a major enzyme called acetlytransferase ....How we handle chemicals that enter our bodies depends on a series of enzymes that are responsible for breaking down the chemicals and eliminating them. The activity of many of these enzymes varies between individuals so our responses to chemicals and drugs is different for each individual. Some of the enzymes vary because of inherited mutations, but others vary because of the diets we eat and the environment in which we live. This project will investigate a major enzyme called acetlytransferase that has been implicated as a risk factor in diseases such as cancer, asthma, liver cirrhossis and adverse drug reactions. We plan to look at the enzyme in cells and determine what environmental factors contribute to its variation between individuals, and how this impacts on the genetic mutations that have been found in its gene. From these studies, we will have a much better undersanding of how different people metabolise foreign chemicals, and should be able to predict those most at risk of certain diseases.Read moreRead less
Glycine Transporters regulate the concentration of glycine in the spinal cord and brain. It has been suggested that elevating glycine levels in these regions may be useful in treating pain and schizophrenia. This project will provide the basis for the development of new glycine transport inhibitors that may be used to treat these conditions.
Pharmacological Targeting Of Arylamine N-Acetyltransferase I
Funder
National Health and Medical Research Council
Funding Amount
$474,653.00
Summary
This project will investigate a novel approach to controlling how cancer cells grow and spread. It plans to study whether a protein termed N-acetyltransferase is a key to determining whether cancer cells can change thier characteristics, allowing them to invade other tissues. In addition, novel approaches to target this protein are proposed. If successful, the work outlined in this project will open new avenues to understanding and trerating cancers.
I am a pharmacologist-cell biologist-molecular biologist and chemist examining the metabolism of iron in normal and neoplastic cells and the development of iron chelators for the treatment of a wide variety of diseases eg., ?-thalassaemia, cancer and Frie
Cytochrome P450 CYP3A Regulation In Humanized Transgenic Mice
Funder
National Health and Medical Research Council
Funding Amount
$376,980.00
Summary
The study of the regulation of human genes is inherently difficult. It is difficult or impossible to gain access to many body tissues in either healthy or sick individuals to examine coordinated gene function (or dysfunction). For this reason, it is often the case that we have a much better understanding of gene function in species such as rats and mice, the most common animal environments for biomedical research. However, findings in animals often fail to meaningfully mirror what occurs in man. ....The study of the regulation of human genes is inherently difficult. It is difficult or impossible to gain access to many body tissues in either healthy or sick individuals to examine coordinated gene function (or dysfunction). For this reason, it is often the case that we have a much better understanding of gene function in species such as rats and mice, the most common animal environments for biomedical research. However, findings in animals often fail to meaningfully mirror what occurs in man. To progress our understanding of human genes we need to develop models that more faithfully reproduce the human situation in an environment that is amenable to both manipulation and close examination, such as the novel 'humanised' mouse models described in this application. This application deals with the regulation genes that control liver enzymes belonging to the human cytochrome P450 3A (CYP3A) subfamily. These enzymes are present in several tissues including liver, gut, lung and breast. They form the main disposal pathway for foreign chemicals such as drugs, environmental pollutants and some cancer causing chemicals. In addition they are involved in the breakdown of several important internally produced substances, such as steroid hormones. Altered formation of CYP3A enzymes can have a dramatic impact on the action of many important drugs and may predispose to some forms of cancer. In this project, we will insert the genes for all four human CYP3A enzymes into mice. We expect that these 'humanised' mouse models will effectively enable the human situation to be studied in a convenient animal model and allow detailed studies to be performed. A knowledge of the mechanisms involved in CYP3A enzyme formation is of particular importance to the fields of drug and steroid metabolism (both in health and in disease states), liver diseases and foetal pharmacology. In addition, these models will provide a new and useful tool for drug development.Read moreRead less