Shedding Light on Alcoholism October 15, 2010Posted by wframe488 in Behavior, Biology.
Scientists today are investigating the relationships between stress and the over use of alcohol. Alcoholism has been an ongoing problem since the Egyptians discovered wine 10,000 years ago. According to the Department of Psychopharmacology, at the University of Heidelberg, in Germany, alcohol consumption is an essential part of daily life of many different societies. The benefits that come from the production, sale, and use of these alcoholic beverages have been found to be detrimental to these societies. The World Health Organization ranks alcohol as one of the primary causes of disease and health problems in industrialized countries.
Alcoholism is an addictive behavior that arises from molecular physiology, according to Sillaber, “Alcohol-related diseases, especially alcoholism, are the result of cumulative responses to alcohol exposure, the genetic make-up of an individual, and the environmental perturbations over time”. In 2002 Sillaber and his colleagues published a scientific paper titled “Enhanced and Delayed Stress-Induced Alcohol Drinking in Mice Lacking Functional CRH1 Receptors.” With this study they found that there is a relationship between stress and drinking alcohol for the average mouse. They studied corticotropin-releasing hormone (CRH) and how it mediates responses to stress and alcohol intake. What I want to know is why on earth these mice are drinking alcohol? …but anyway, mice that lacked an efficient CRH1 receptor underwent progressive alcohol intake. With repeated stress added to the mice this particular drinking behavior persisted throughout their life. They discovered that this behavior was associated with the up-regulation of N-methyl-D-aspartate receptor (NMDA) subunit (NR2B). So, alterations of the CRH1 receptor and changes in NR2B subunits could compose a genetic risk factor for alcoholism.
Cortisol is a steroid hormone or glucocorticoid produced by the adrenal gland. It is released in response to stress, and low levels of blood glucocorticoids. Its primary functions are to increase blood sugar through gluconeogenesis, suppress the immune system, and aid in fat, protein, and carbohydrate metabolism. The secretion of corticotropin-releasing hormone (CRH) by the hypothalamus triggers pituitary secretion of adrenal corticotrophic hormone (ACTH); ACTH is carried by the blood to the adrenal cortex where it triggers glucocorticoid secretion. It’s a long and confusing process but in the end cortisol should be released. In the study by Sillaber the CRH1 receptors of the mice were ineffective which meant that the pituitary gland was not being stimulated to produce the glucocorticoid, cortisol, to deal with the stressful environment. This then lead to excessive alcohol consumption by the mice. This idea sheds light on a possible influence in humans.
Let’s face it we are all stressed at one point or another and we all have different ways of dealing with this stress. Some go fishing, others listen to music, or exercise, but some of us drink alcohol… and lots of it. According to the results of the Sillaber study it is possible that CRH deficiency could be a factor in human alcoholism. Check out the blog by my friend Joe for additional information.