Alcohol and Alcoholism Advance Access originally published online on August 30, 2005
Alcohol and Alcoholism 2005 40(6):485-493; doi:10.1093/alcalc/agh196
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PROTEIN ADDUCT SPECIES IN MUSCLE AND LIVER OF RATS FOLLOWING ACUTE ETHANOL ADMINISTRATION
1 Department of Biomedical Sciences, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK, 2 Alcohol Research Unit, Department of Biochemistry and Molecular Biology, The University of Queensland, Brisbane, Queensland, QLD 4072, Australia and 3 Nutrition, Food and Health Research Centre, King's College London, 150 Stamford Street, London SE1 9NN, UK
* Author to whom correspondence should be addressed at: Department of Biomedical Sciences, University of Westminster, 115 New Cavendish Street, London W1W 6UW UK. Tel: +44 020 7911 5000 (ext. 3543); Fax: +44 020 7911 5087; E-mail: v.b.patel{at}westminster.ac.uk
(Received 2 March 2005; first review notified 29 March 2005; in revised form 15 July 2005; accepted 26 July 2005)
Aims: Previous immunohistochemical studies have shown that the post-translational formation of aldehyde–protein adducts may be an important process in the aetiology of alcohol-induced muscle disease. However, other studies have shown that in a variety of tissues, alcohol induces the formation of various other adduct species, including hybrid acetaldehyde–malondialdehyde–protein adducts and adducts with free radicals themselves, e.g. hydroxyethyl radical (HER)–protein adducts. Furthermore, acetaldehyde–protein adducts may be formed in reducing or non-reducing environments resulting in distinct molecular entities, each with unique features of stability and immunogenicity. Some in vitro studies have also suggested that unreduced adducts may be converted to reduced adducts in situ. Our objective was to test the hypothesis that in muscle a variety of different adduct species are formed after acute alcohol exposure and that unreduced adducts predominate. Methods: Rabbit polyclonal antibodies were raised against unreduced and reduced aldehydes and the HER–protein adducts. These were used to assay different adduct species in soleus (type I fibre-predominant) and plantaris (type II fibre-predominant) muscles and liver in four groups of rats administered acutely with either [A] saline (control); [B] cyanamide (an aldehyde dehydrogenase inhibitor); [C] ethanol; [D] cyanamide+ethanol. Results: Amounts of unreduced acetaldehyde and malondialdehyde adducts were increased in both muscles of alcohol-dosed rats. However there was no increase in the amounts of reduced acetaldehyde adducts, as detected by both the rabbit polyclonal antibody and the RT1.1 mouse monoclonal antibody. Furthermore, there was no detectable increase in malondialdehyde–acetaldehyde and HER–protein adducts. Similar results were obtained in the liver. Conclusions: Adducts formed in skeletal muscle and liver of rats exposed acutely to ethanol are mainly unreduced acetaldehyde and malondialdehyde species.