Alcohol and Alcoholism Advance Access originally published online on March 14, 2005
Alcohol and Alcoholism 2005 40(3):163-171; doi:10.1093/alcalc/agh097
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CHRONIC CONSUMPTION OF ETHANOL LEADS TO SUBSTANTIAL CELL DAMAGE IN CULTURED RAT ASTROCYTES IN CONDITIONS PROMOTING ACETALDEHYDE ACCUMULATION
Laboratoire ORSOX (Oligoéléments et Résistance au Stress Oxydant induit par les Xénobiotiques) UMR UJF/CEA-LCR CEA 8M, Université Joseph Fourier, Domaine de la Merci, 38706 La Tronche Cedex, France
* Author to whom correspondence should be addressed at: Fédération de Toxicologie Clinique et Biologique, CHU de Grenoble, 38043 Grenoble Cedex, France. Tel.: (33) 4 76 765783; Fax: (33) 4 76 765177; E-mail: Luc.Barret{at}ujf-grenoble.fr
(Received 7 October 2003; first review notified 15 December 2003; in revised form 11 February 2004; accepted 1 September 2004; Advance Access publication 17 March 2005)
Aims: This study aimed at comparing the cerebral cytotoxicity of ethanol and its main metabolite acetaldehyde after acute or chronic exposures of rat astrocytes in primary culture. Methods: Cytotoxicity was evaluated on the cell reduction of viability (MTT reduction test) and on the characterization of DNA damage by single cell gel electrophoresis (or comet assay). Results: Changes in astrocyte survival and in DNA integrity only occurred when the astrocytes were chronically exposed to ethanol (20 mM; 3, 6 or 9 days). On the other hand, viability and DNA integrity were deeply affected by acute exposure to acetaldehyde. Both effects were dependent on the concentration of acetaldehyde. The cytotoxic effect of acetaldehyde was also indirectly evaluated after modifications of the normal ethanol metabolism by the use of different inducers or inhibitors. In presence of ethanol, the concomitant induction of catalase (i.e. by glucose oxidase) and inhibition of aldehyde dehydrogenase (i.e. by methylene blue) led to acetaldehyde accumulation within cells. It was followed by both a reduction in viability and a substantial increase in DNA strand breaks. Conclusions: These data were thus consistent with a possible predominant role of acetaldehyde during brain ethanol metabolism. On the other hand, the effects observed after AMT could also suggest a possible direct ethanol effect and a role for free radical attacks. These data were thus consistent with a possible predominant role of acetaldehyde during brain ethanol metabolism. On the other hand, the effects observed after AMT could also suggest a possible direct ethanol effect and a role for free radical attacks.