Involvement of adenosine in ethanol-induced changes in G-protein expression in NG108-15 cells?

Reference:

Williams, R. J., Veale, M. A. and Kelly, E., 1993. Involvement of adenosine in ethanol-induced changes in G-protein expression in NG108-15 cells? Alcohol and Alcoholism: Supplement, 2, pp. 431-435.

Related documents:

Related URLs:

• http://www.ncbi.nlm.nih.gov/pubmed/7748334

Abstract

Previous work has suggested that adenosine may be involved in ethanol-induced heterologous desensitization of adenylate cyclase in NG108-15 cells. It was proposed that chronic ethanol causes adenosine to accumulate extracellularly, activating adenosine A2 receptors and so leading to a reduction in Gs alpha mRNA and Gs alpha protein (Nagy et al., 1989). In this study we further investigated the effect of chronic ethanol on G-protein expression in NG108-15 cells. Pretreatment of NG108-15 cells with ethanol (200 mM, 48h) reduced membrane levels of Gs alpha and Gi alpha but increased Go alpha expression. The effects of ethanol on alpha-subunit expression were not reversed by adenosine deaminase and could not be mimicked by the adenosine agonist 5'- (n-ethyl)-carboxamidoadenosine (NECA). Chronic ethanol pretreatment did not appear to reduce the levels of Gs alpha or Gi alpha 2 mRNA. This same ethanol pretreatment reduced cell proliferation and increased differentiation without altering cell viability. Adenosine deaminase did not reverse any of these effects. These results indicate that ethanol differentially regulates G-protein alpha-subunit expression and induces morphological alterations in these cells independently of extracellular adenosine.

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