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This Article Full Text Full Text (PDF) All Versions of this Article: jas.2007-0456v1 86/14_suppl/E217    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Dayton, W. R. Articles by White, M. E. PubMed PubMed Citation Articles by Dayton, W. R. Articles by White, M. E.

Cellular and molecular regulation of muscle growth and development in meat animals^1,2

Department of Animal Science, University of Minnesota, St. Paul 55108

³ Corresponding author: wdayton{at}umn.edu

Although in vivo and in vitro studies have established that anabolic steroids, transforming growth factor-β (TGF-β), and myostatin affect muscle growth in meat-producing animals, their mechanisms of action are not completely understood. Anabolic steroids have been widely used as growth promoters in feedlot cattle for over 50 yr. A growing body of evidence suggests that increased muscle levels of IGF-I and increased muscle satellite cell numbers play a role in anabolic steroid enhanced muscle growth. In contrast to anabolic steroids, the members of the TGF-β-myostatin family suppress muscle growth in vivo and suppress both proliferation and differentiation of cultured myogenic cells. Recent evidence suggests that IGFBP-3 and IGFBP-5 play a role in mediating the proliferation-suppressing actions of both TGF-β and myostatin on cultured myogenic cells. Consequently, this review will focus on the roles of IGF-I and IGFBP in the cellular and molecular mechanisms of action of anabolic steroids and TGF-β and myostatin, respectively.

Key Words: muscle • anabolic steroid • myostatin • insulin-like growth factor-I • insulin-like growth factor binding protein • transforming growth factor-β