Oxidative Stress in Alcoholic Cardiomyopathy

描述（由申请人提供）：

DESCRIPTION (provided by applicant): Alcoholism is one of the top public health problems in the U S Although alcohol abuse can cause cardiac muscle dysfunction with a relatively high prevalence, the early disease states usually go unrecognized clinically, since patients seldom experience any symptom of congestive heart failure When the extent of cardiac dysfunction becomes clinically evident, the disease has invariably resulted in a severely enlarged heart (dilated cardiomyopathy) commonly described as alcohol-induced heart muscle disease or alcoholic cardiomyopathy Experimental data generally supports the notion that alcohol is the sole causative agent in the development of this disease. However, there is a growing body of evidence to suggest that cardiomyopathy, regardless of etiology, is directly or indirectly related to an increased oxidative stress to the heart as a common final pathway. Since selenium and vitamin deficiencies are common among alcoholics, possibly as a result of malnutrition and/or malabsorption, it is hypothesized that alcoholic cardiomyopathy is caused by long-term alcohol abuse in the setting of nutritional deficiency involving both selenium and vitamin E. Since selenium and vitamin E are important anti-oxidants, a deficiency state involving these two anti-oxidants will result in a decrease in anti-oxidant defense. Alcohol consumption is well recognized to be associated with an increase in free radical production. Under these two specific nutritional deficiency states, the resultant decrease in anti-oxidant defense may not be adequate in quenching/removing the free radicals generated from high alcohol intake. This resultant increase in oxidative stress may damage various organs such as the heart leading to cardiac contractile dysfunction manifested clinically as congestive heart failure. Therefore, the present study is designed to confirm such hypothesis by feeding rats long-term high-dose alcohol and diets deficient in selenium and/or vitamin E. Pressure-volume conductance and histological studies will be performed when echocardiographic study indicates a decrease. Biochemical and molecular studies of the cardiomyopathic heart will then be performed in cardiac function and ventricular enlargement after 40 weeks of feeding. They include measuring 4-hydroxy-2-nonenal, a major product and biomarker of lipid peroxidation. To investigate if increased apoptosis occurs as a result of increased oxidative stress, two consecutive measurements of apoptotic index and caspase 3 release will be conducted first when hypertrophy is detected from serial echocardiography and again with the development of alcoholic cardiomyopathy. The results obtained from this study will not only provide unique information regarding the pathogenetic mechanism involved in the development of alcoholic cardiomyopathy, but may also yield a new model of alcoholic cardiomyopathy suitable for future studies to evaluate therapeutic options such as selenium-, vitamin E supplementation, specific anti-metabolites of alcohol, specific anti-lipid peroxidation inhibitor or specific anti-apoptosis agent for preventing the development of alcoholic cardiomyopathy as well as reversing the far more prevalent yet frequently undiagnosed stage of alcoholic cardiomyopathy.