92 AC activity in animal and human cells and tissues is altered by acute and chronic ethanol treatment.93 AC activity can be measured in both platelets and lymphocytes, although the results

can differ depending on which in vitro model is used.11 Lower cAMP production following chemical stimulation of platelets or white blood cells has been observed among alcoholics and individuals with a family history of alcoholism.94 The production of cAMP in chemically stimulated cells has been investigated Inhibitors,research,lifescience,medical in children of alcoholics who might share lower levels of Gs protein-stimulated cAMP production with their alcoholic relatives. The children of alcoholic parents were found to have lower platelet AC activity in comparison to children of nonalcoholic parents.95 The risk of alcoholism could be a result of low innate activity of AC, with acute alcohol Inhibitors,research,lifescience,medical causing a temporary stimulation and subsequent abstinence producing the opposite effect. Thus, this might promote more alcohol intake in attempt to compensate for low AC activity in individuals predisposed to alcohol selleck products dependence or already dependent individuals.95-97 As already mentioned, several studies Inhibitors,research,lifescience,medical have shown that AC activity in platelets or lymphocytes of alcohol-dependent

individuals is less responsive to various stimulations, such as that by forskolin, compared to non-alcoholdependent individuals.98-103 However, it is not completely clear if these differences are a consequence of alcohol drinking or an indicator of susceptibility to alcohol Inhibitors,research,lifescience,medical dependence. Recent studies have shown that platelet AC activity decreases

after a period of abstinence from heavy drinking.104 Furthermore, AC activity in alcohol-dependent subjects was lower for those who abstained for a period of time prior to testing.104 Various alcohol-related factors that affect AC activity level may compromise its utility as an endophenotype to study predisposition to alcohol dependence.104 Inhibitors,research,lifescience,medical β-Endorphins The endogenous opioids, which include β-endorphins, are proteins that bind to the opioid receptors. Alcohol is believed to stimulate the release of certain opioid peptides, which could interact with opioid receptors in regions of the brain associated with reward and positive reinforcement.105 Increased activity of brain β-endorphin (enkephalin) opioid peptide systems may be important for initiating and maintaining high levels of alcohol consumption.105 Subjects first with a family history of alcoholism presented with lower concentrations of plasma β-enodorphin in the early morning hours and a more pronounced increase in pituitary β-endorphin release after ingestion of moderate doses of alcohol.106,107 When examining the heritability of hormonal responses, a twin study found that β-endorphin response to alcohol was heritable.108 Decreased β-endorphin has been noted in the cerebrospinal fluid (CSF) of abstinent alcoholics.