Appetite-regulating hormones, alcohol dependence and craving in a rodent model

Introduction Appetite-regulating hormones have long been the focus of research on alcohol dependence and craving. The leptin-melanocortin pathway, with its hormones leptin, alpha-melanocyte stimulating hormone (alpha-MSH) and the associated receptors, plays a central role. Could these peptide hormones be markers of craving in alcohol withdrawal?

Methods In a rodent model for alcohol addiction, we examined the plasma levels of the hormones alpha-MSH and leptin and their possible epigenetic regulation at various times during the six-day alcohol withdrawal.

Results In alcohol withdrawal, neither alcohol-consuming animals nor control animals showed changes in the leptin levels. In contrast, the alpha-MSH levels in alcohol withdrawal were significantly reduced, but remained unchanged in the control animals. The methylation of the leptin promoter was significantly reduced at the beginning of alcohol withdrawal compared to the controls. This difference disappeared within the six-day withdrawal.

Conclusion In the animal experiment presented, a significant decrease in the appetite-reducing hormone alpha-MSH was observed for the first time in alcohol withdrawal, despite free access to food. The upstream hormone leptin, which has an activating effect on the alpha-MSH precursor proopiomelanocortin, remained unchanged. Could alpha-MSH be a hormonal correlate of craving? Further investigation with changed withdrawal periods must follow to answer this question.