Chronic ethanol consumption impairs the circadian rhythm of pro-opiomelanocortin and period genes mRNA expression in the hypothalamus of the male rat

J Neurochem. 2004 Mar;88(6):1547-54. doi: 10.1046/j.1471-4159.2003.02300.x.

Abstract

Certain psychiatric disorders are known to alter the body's biological rhythms. However, currently, very little information is known about the effect of chronic ethanol administration on the circadian clock or the rhythm of beta-endorphin-containing neurons that participate in the control of the reward and reinforcement of alcohol drinking. Here, we report that administration of ethanol, via a liquid diet paradigm for a period of 2 weeks, abolishes the circadian rhythm of pro-opiomelanocortin mRNA expression of beta-endorphin neurons in the arcuate nucleus of the hypothalamus. The circadian expression of the clock governing rat period genes (rPeriod1 mRNA and rPeriod2 mRNA) in the arcuate nucleus was significantly altered, suggesting that ethanol administration disrupted the internal clock. Moreover, ethanol consumption altered the circadian rhythms of rPeriod2 and rPeriod3 mRNA levels in the suprachiasmatic nucleus, suggesting that ethanol also affected the function of the central pacemaker. Our findings identified the vulnerability of the body's clock machinery and its opioidergic system to chronic alcohol drinking.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alcohol-Induced Disorders, Nervous System / chemically induced
  • Alcohol-Induced Disorders, Nervous System / metabolism
  • Alcohol-Induced Disorders, Nervous System / physiopathology
  • Animals
  • Arcuate Nucleus of Hypothalamus / drug effects
  • Arcuate Nucleus of Hypothalamus / metabolism
  • Cell Cycle Proteins
  • Chronobiology Disorders / chemically induced*
  • Chronobiology Disorders / metabolism
  • Chronobiology Disorders / physiopathology
  • Circadian Rhythm / drug effects
  • Ethanol / pharmacology*
  • Gene Expression Regulation / drug effects*
  • Hypothalamus / drug effects*
  • Hypothalamus / metabolism
  • Male
  • Nuclear Proteins / genetics*
  • Period Circadian Proteins
  • Pro-Opiomelanocortin / genetics*
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Suprachiasmatic Nucleus / drug effects
  • Suprachiasmatic Nucleus / metabolism
  • Transcription Factors

Substances

  • Cell Cycle Proteins
  • Nuclear Proteins
  • Per1 protein, mouse
  • Per1 protein, rat
  • Per2 protein, mouse
  • Per2 protein, rat
  • Per3 protein, mouse
  • Per3 protein, rat
  • Period Circadian Proteins
  • RNA, Messenger
  • Transcription Factors
  • Ethanol
  • Pro-Opiomelanocortin