THE EFFECT OF AN ACUTE ETHANOL EXPOSURE ON THE RAT-BRAIN POMC OPIOPEPTIDE SYSTEM

Endogenous peptides with a high affinity for opiate receptors located in the central nervous system have been postulated to play a role in t he etiology of alcoholism or in other addictive diseases. Effects of d ifferent doses of ethanol (EtOH) at different time points post-EtOH ad ministration on hypothalamic and hindbrain beta-endorphin-like peptide (beta-EPLP) content in male rats were measured by radioimmunoassay (R IA). A single EtOH exposure resulted in an increase in hypothalamic an d a decrease in the hindbrain beta-EPLP levels. In another set of expe riments, proopiomelanocortin (POMC) synthesis in the hypothalamus was measured by assaying both POMC primary transcript and mature mRNA. No changes in primary transcript or mature POMC hypothalamic mRNA were de tected. Based on the results from this experiment we conclude that an acute EtOH exposure affects the rat hypothalamic POMC opiopeptide syst em by increasing levels of beta-EPLP and this increase in levels is no t related to an increase in synthesis. (C) 1998 Elsevier Science Inc.