• Energy Research

The numerous adverse effects of ethanol abuse and ethanol withdrawal on biological systems are well documented. Conversely, the understanding of the molecular mechanisms underlying these pathological effects is still incomplete. This study was undertaken to investigate the effects of short-term chronic ethanol administration and ethanol withdrawal on the molecular structure and function of hippocampal tissue, a brain region important for mnemonic processes and known to be highly susceptible to ethanol intoxication.Ethanol was administered to adult Wistar rats by intragastric intubation for 15 days with a stepwise increase in the daily dose from 6 to 12 g/kg body weight, with the highest dose delivered for the last 2 days only. The total daily dose of ethanol was divided into 3 equal portions administered 4 hours apart. Animals were sacrificed by decapitation at 4, 24, and 72 hours after the last ethanol administration to examine potential effects of ethanol intoxication and ethanol withdrawal. Ethanol-related molecular changes were monitored by Fourier transform infrared (FT-IR) spectroscopy.Significant changes in the hippocampal content, structure, and function of lipids, proteins, and nucleic acids were recorded under ethanol intoxication. Seventy-two hours after the cessation of ethanol administration, during the late phase of withdrawal, alterations in the macromolecules' content and conformational changes in protein and nucleic acid structure ameliorated, while the changes in macromolecular ratios, lipid order, and dynamics aggravated.Our results suggest that 15 days of binge-like drinking resulting in the high blood alcohol concentration (varying in the dose-dependent manner between 253 and 606 mg/dl) produced a strong physical dependence manifested mainly by the changes in lipid profiles pointing toward withdrawal-induced oxidative stress. These results show that ethanol withdrawal may cause equal to or even more severe brain damage than the ethanol itself, which should be considered when designing antialcohol therapies.

AbstractThe structural effects of vitamin A‐deficiency were examined on the molecular profiles of biomolecules of male rat hippocampus during prolonged ethanol intake/withdrawal using FT‐IR spectroscopy coupled with chemometrics. Liquid ethanol diet with/without vitamin A was maintained to adult rats for 3‐months. The rats were decapitated at different ethanol withdrawal times and FT‐IR spectra were obtained. Ethanol consumption/withdrawal produced significant changes in proteins' conformations, while having insignificant structural effects on lipids. In vitamin A deficiency, ethanol produced structural changes in lipids by lipid ordering especially in the early‐ethanol withdrawal. Furthermore, an increase in lipid and protein content, saturated/unsaturated lipid ratio, a decrease in nucleic acids content and decrease in membrane fluidity were observed. These changes were less severe in the presence of Vitamin A. This study is clinically important for individuals with vitamin A deficiency because they have to be more cautious when consuming alcohol to protect themselves from cognitive dysfunctions.