Why is ethanol (alcohol) a factor to study?
Many know that when alcohol is consumed the liver is responsible for 'clearing'
alcohol from the system. However, many people don't realize that alcohol is
an oxidant and the liver is the site of detoxification. Before detoxification,
while alcohol is in the bloodstream, it comes in contact with every cell and
oxidizes surface components. In lung cells interaction between ethanol
and the lungs may be most readily recognized by the fumes on the breath of
someone who has been drinking alcoholic beverages.
Lung cells undergo oxidative damage due to chronic ethanol ingestion (Guidot, 2000). The accumulation of damage might be expected to be seen as symptoms of lung problems and studies have shown that alcoholics have a higher prevalence of Acute Respiratory Distress Syndrome (ARDS). The cause(s) of ARDS are not known but the condition is characterized by reduced lung function that could be linked to other environmental factors such as prolonged ozone exposure or ethanol itself (Brown, 2001). Our cell culture approach uses amodel system where we can characterize the combined effects of ethanol and ozone under controlled conditions.
What is Ethanol?
- Ethanol is a volatile, colorless alcohol commonly used as a solvent, an antiseptic, and a psychoactive drug.
- Ethanol is one of the most commonly abused drugs in the world (Meropol, 1996)
Ethanol in the Body
Ethanol’s main target is the central nervous system, where it binds to GABA receptors to have a number of affects, based off the above concentrations (Chastain, 2006)
An individual's gender, age, body weight, ancestry and 'experience' with ethanol will all play a role in determining the extent to which physical abilities will be impaired. Note that, system-wide, alcohol is a depressant and any level of consumption can change coordination and reaction time. In addition, consumption of alcohol adds an oxidative stressor to the blood stream-- the extent to which this stress causes problems in lung cells is the focus of our research.
For more information, check out this interesting powerpoint presentation on the physiological effects of ethanol (Dr K Strang, UW-Madison)
Ethanol Metabolism /Oxidation
The liver first uses alcohol dehydrogenase to metabolize ethanol into acetaldehyde and ROS (Ginter, 2009)
- Accumulation of acetaldehyde (which, like ethanol, is toxic) has been widely
thought to be associated with the hangover-like symptoms associated with
high alcohol consumption (Ginter, 2009)
- ROS (reactive oxygen species) are strong cellular oxidants that are necessary in low concentration but in higher concentrations cause the breakdown of proteins, DNA and lipids. We hypothesize that having a large, external source of ethanol (drinking alcoholic beverages) would lead to high concentrations of ROS and increased cell damage.
Ethanol, the Lung, and Oxidative Stress
Studies have shown that ethanol causes oxidative stress in lung cells through production of reactive oxygen species in the mitochondria (Guidot and Brown, 2000). Also ethanol can diminish the amount of glutathione available for antioxidant activity (Guidot and Brown, 2000).
Some college campuses are known as 'party schools' amd on others there is can be a culture of 'work hard, play hard' (often interpreted by students as 'party hard') We are interested in the effect that sustained or binge exposure to ethanol has on the function of lung cells. Using a cell culture model of chronic and acute ('binge') alcohol administration we study changes in cell function and damage caused by the oxidant ethanol and its metabolic byproducts