caa a22 4500 475745280 CHVBK 20180406123511.0 cr unu---uuuuu 170329e20001101xx s 000 0 eng 10.1023/A:1010336624154 doi (NATIONALLICENCE)springer-10.1023/A:1010336624154 Protein and mRNA Levels of the Myosin heavy chain Isoforms Iβ, IIa, IIx and IIb in Type I and Type II Fibre-predominant Rat Skeletal Muscles in response to Chronic Alcohol Feeding [Elektronische Daten] [M. Reilly, G. McKoy, D. Mantle, T. Peters, G. Goldspink, V. Preedy] Alcoholic myopathy occurs in between one and two-thirds of all alcohol misusers and is thus one of the most prevalent muscle disorders (2000 cases per 100,000 population). It is characterised by myalgia, muscle weakness and loss of lean tissue mass. Histological features include a reduction in the diameter of Type II muscle fibres, particularly the IIb fibre subset. In contrast, Type I fibres are relatively protected. It is possible that the myopathy is due to perturbations in myosin protein and mRNA expression. To test this hypothesis, we fed rats a liquid diet containing 35% of calories as ethanol. Control rats were pair-fed identical amounts of the same diet in which ethanol was replaced by isocaloric glucose. At the end of 6 weeks, total myofibrillary proteins and myosin heavy chain (MyoHC) Iβ, IIa, IIx and IIb protein and mRNA were analysed in the plantaris (Type II fibre-predominant) and soleus (Type I fibre-predominant) muscles. The data showed that there were significant reductions in the total myofibrillary protein content in the plantaris of ethanol fed rats compared to pair-fed controls (P < 0.05). These changes in the plantaris were accompanied by reductions in total myosin (P < 0.025), as a consequence of specific reductions in the Iβ, (P < 0.01), IIx (P < 0.05) and IIb (P < 0.05) protein isoforms. The mRNA levels of Iβ were significantly reduced in the plantaris (P < 0.05). However, mRNA levels of IIa, IIx and IIb in the plantaris were not significantly affected by alcohol feeding. Other changes in the plantaris included significant reductions in desmin (P < 0.01), actin (P < 0.025), and troponin-I (P < 0.05) compared to pair-fed controls. In the soleus, the only significant changes related to a fall in Iβ mRNA levels and a decline in troponin-C content. We conclude that in the rat, alcoholic myopathy is a feature of Type II fibre rich muscles and is accompanied by multiple protein changes. The decline in specific myosin protein levels, such as IIx and IIb in the absence of corresponding reductions in their mRNAs, is probably due to altered proteolysis or more likely reductions in translational efficiencies, rather than changes in transcription. Kluwer Academic Publishers, 2000 Reilly M. Molecular and Cellular Protein Biochemistry Laboratory, Department of Nutrition and Dietetics, King's College, 150 Stamford Street, SE1 9NN, London, UK aut McKoy G. Department of Developmental Anatomy, The Royal Free Hospital, Roland Hill Street, Hampstead, London, UK aut Mantle D. Department of Neurochemistry, Regional Neurosciences Centre, Newcastle General Hospital, Newcastle-Upon-Tyne, UK aut Peters T. Department of Clinical Biochemistry, Kings College School of Medicine, Denmark Hill, SE5 9PJ, London, UK aut Goldspink G. Department of Developmental Anatomy, The Royal Free Hospital, Roland Hill Street, Hampstead, London, UK aut Preedy V. Molecular and Cellular Protein Biochemistry Laboratory, Department of Nutrition and Dietetics, King's College, 150 Stamford Street, SE1 9NN, London, UK aut Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/8(2000-11-01), 763-773 0142-4319 21:8<763 2000 21 10974 https://doi.org/10.1023/A:1010336624154 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1010336624154 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Reilly M. Molecular and Cellular Protein Biochemistry Laboratory, Department of Nutrition and Dietetics, King's College, 150 Stamford Street, SE1 9NN, London, UK aut NATIONALLICENCE 700 1- McKoy G. Department of Developmental Anatomy, The Royal Free Hospital, Roland Hill Street, Hampstead, London, UK aut NATIONALLICENCE 700 1- Mantle D. Department of Neurochemistry, Regional Neurosciences Centre, Newcastle General Hospital, Newcastle-Upon-Tyne, UK aut NATIONALLICENCE 700 1- Peters T. Department of Clinical Biochemistry, Kings College School of Medicine, Denmark Hill, SE5 9PJ, London, UK aut NATIONALLICENCE 700 1- Goldspink G. Department of Developmental Anatomy, The Royal Free Hospital, Roland Hill Street, Hampstead, London, UK aut NATIONALLICENCE 700 1- Preedy V. Molecular and Cellular Protein Biochemistry Laboratory, Department of Nutrition and Dietetics, King's College, 150 Stamford Street, SE1 9NN, London, UK aut NATIONALLICENCE 773 0- Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/8(2000-11-01), 763-773 0142-4319 21:8<763 2000 21 10974 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer