ORIGINAL CONTRIBUTION Basic Res Cardiol 95: 199 – 207 (2000) © Steinkopff Verlag 2000 Vera Regitz-Zagrosek Antonius Kyriakopoulos Klaus-Peter Pleißner Peter Jungblut Eckart Fleck Dietrich Behne Effects of selenium deficiency on the rat myocardial protein pattern – investigation by two-dimensional gel electrophoresis Abstract Dietary selenium deficiency represents an etiological factor in “Keshan disease”, a distinct form of an endemic cardiomyopathy. The biochemical effects of selenium depletion in the myocardium are, however, not yet known. Therefore, we investigated the changes in the myocardial protein pattern in rats after long-term selenium deficiency. The myocardial proteins were analyzed in samples from five selenium-depleted rats (Se-deficient group) and five rats supplied with adequate amounts of the element (Se-adequate group). Isoelectric focusing (IEF) with carrier ampholytes on large 2-DE gels was used for the separation of proteins in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for the second dimension. The protein patterns were evaluated by means of a computer-assisted gel analysis system. The biochemical identification of the proteins of interest was achieved by matrix-assisted laser desorption/ionization mass spectrometry (MALDI) or immunoblotting. On average, 588 ± 68 protein spots were found on the gels. No significant dif- ference in spot numbers existed between the groups. A pattern of 270 spots with identical positions was found on every gel; 247 of these spots were not saturated and used for quantitative comparison. Thirty-five, i.e., 14 %, differed significantly in their relative intensity in the two groups. Twenty-eight protein spots were decreased in the Se-deficient group and seven were increased. Sarcomeric creatine kinase M chain, -myosin heavy chain (-MHC) and myosin light chain 1 and 2 (MLC 1 and 2) were largely decreased in Se-deficiency. Three protein spots were increased by more than twofold or appeared only in the Se-deficient group. A mitochondrial creatine kinase was identified in this group. The results suggest that selenium deficiency affects myocardial energy metabo- lism and contractile proteins. These changes probably reflect non-specific alterations in heart failure. Key words Rat – myocardium – selenium deficiency – two-dimensional gel electrophoresis – computer-assisted image analysis – protein identification Prof. Dr. V. Regitz-Zagrosek () K.-P. Pleißner · E. Fleck Innere Medizin/Kardiologie Humboldt Universität Charité Campus Virchow-Klinikum und Deutsches Herzzentrum Berlin Augustenburger Platz 1, D-13353 Berlin E-mail: Zagrosek@dhzb.de A. Kyriakopoulos · D. Behne Hahn-Meitner-Institut Berlin Abt. „Spurenelemente in Gesundheit und Ernährung“ Glienicker Str. 100, D-14109 Berlin P. Jungblut Max-Planck-Institut für Infektionsbiologie Monbijoustr. 2, D-10117 Berlin Received: 19 February 1997 Returned for 1. revision: 7 April 1997 1. Revision received: 29 January 1999 Returned for 2. revision: 18 February 1999 2. Revision received: 21 December 1999 Accepted: 6 January 2000 BRC 200