Ethanol-induced impairments in receptor-mediated endocytosis of asialoorosomucoid in isolated rat hepatocytes: time course of impairments and recovery after ethanol withdrawal

Alcohol Clin Exp Res. 1989 Apr;13(2):258-63. doi: 10.1111/j.1530-0277.1989.tb00323.x.

Abstract

Chronic ethanol administration markedly impairs the process of receptor-mediated endocytosis (RME) of a representative asialoglycoprotein, asialoorosomucoid (ASOR), by the liver. In this study, we further characterized these impairments by identifying the time of onset for ethanol-induced changes in RME as well as establishing the time course for recovery to normal endocytotic values after ethanol withdrawal. Ethanol administration for 3 days did not alter any aspect of endocytosis examined in this study. After feeding ethanol to rats for 7 days, however, significant decreases in amounts of ligand bound, internalized, and degraded were apparent. These impairments persisted throughout the 5-week feeding study although the effects were somewhat attenuated with more prolonged ethanol feeding. In addition, an accumulation of intracellular receptors was observed in ethanol-fed animals relative to controls after 7 days of ethanol feeding. In all cases, recovery of endocytotic values to control levels was partially completed after 2 to 3 days of refeeding control diet and was fully completed after 7 days of refeeding. These results indicate that ethanol feeding for as little as 7 days profoundly impairs the process of RME by the liver. These impairments can be reversed after refeeding control diet for 7 days.

Publication types

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

MeSH terms

  • Animals
  • Asialoglycoproteins*
  • Endocytosis / drug effects*
  • Ethanol / pharmacology*
  • Humans
  • In Vitro Techniques
  • Iodine Radioisotopes
  • Liver / cytology*
  • Liver / drug effects
  • Orosomucoid / analogs & derivatives*
  • Orosomucoid / metabolism
  • Orosomucoid / pharmacology
  • Rats
  • Time Factors

Substances

  • Asialoglycoproteins
  • Iodine Radioisotopes
  • Orosomucoid
  • asialoorosomucoid
  • Ethanol