Alcohol Withdrawal and Proopiomelanocortin Neuropeptides in an Animal Model of Alcohol Dependence

Neuropsychobiology. 2019;78(3):118-127. doi: 10.1159/000499844. Epub 2019 May 22.

Abstract

Background: Alcohol is one of the leading threats to health worldwide. Craving for alcohol makes abstinence a difficult challenge by maintaining alcohol dependence. Many studies suppose the hypothalamic-pituitary-adrenal axis, especially the proopiomelanocortin (POMC)-derived neuropeptides, to mediate craving during withdrawal in alcohol dependence. Evidence is available that the two POMC proteins, α-melanocyte-stimulating hormone (α-MSH) and β-endorphin (β-END) are altered by alcohol consumption and influence alcohol consumption, respectively.

Objectives: We investigated the dynamics of α-MSH and β-END during alcohol withdrawal and the influence of intraperitoneal administration of either α-MSH or β-END in an established rodent model (Wistar rats) for alcohol dependence.

Results: After long-term alcohol self-administration over 12 months and repeated deprivation periods for 3 days, we found a significant decrease in α-MSH levels during withdrawal in rodents (p = 0.006) compared to controls, while β-END levels remained unchanged. Treatment with intraperitoneally administered α-MSH and β-END did not affect alcohol drinking behavior after deprivation.

Conclusion: We demonstrate the effects of alcohol deprivation on α-MSH in alcohol-dependent rodents, which appear to mimic α-MSH alteration found after fasting periods during appetite regulation. Therefore, low α-MSH levels are a possible indicator for craving in alcohol-dependent individuals and hence would be a potential target for anti-craving treatment.

Keywords: Rat; Alcohol; Proopiomelanocortin; α-Melanocyte-stimulating hormone; β-Endorphin.

MeSH terms

  • Alcohol Drinking
  • Alcoholism / physiopathology*
  • Animals
  • Disease Models, Animal
  • Ethanol / administration & dosage*
  • Male
  • Rats, Wistar
  • alpha-MSH / administration & dosage
  • alpha-MSH / blood
  • alpha-MSH / physiology*
  • beta-Endorphin / administration & dosage
  • beta-Endorphin / blood
  • beta-Endorphin / physiology*

Substances

  • Ethanol
  • alpha-MSH
  • beta-Endorphin