title: Effects of testosterone treatment on markers of skeletal muscle ribosome biogenesis.
abstract: The effects of testosterone (TEST) treatment on markers of skeletal muscle ribosome biogenesis in vitro and in vivo were examined. C2C12myotubes were treated with 100 nm TEST for short-term (24-h) and longer-term (96-h) treatments. Moreover, male 10-month-old Fischer 344 rats were housed for 4 weeks, and the following groups were included in this study: (i) Sham-operated (Sham) rats, (ii) orchiectomised rats (ORX) and (iii) ORX+TEST-treated rats (7.0 mg week-1). For in vitro data, TEST treatment increased c-Myc mRNA expression by 38% (P = 0.004) after 96 h, but did not affect total RNA, 47S pre-rRNA, Raptor mRNA, Nop56 mRNA, Bop1 mRNA, Ncl mRNA at 24 h or 96 h following the treatment. For in vivo data, ORX decreased levator ani/bulbocavernosus (LABC) myofibril protein versus Sham (P = 0.006), whereas ORX+TEST (P = 0.015) rescued this atrophic effect. ORX also decreased muscle ribosome content (total RNA) compared to Sham (P = 0.046), whereas ORX+TEST tended to rescue this effect (P = 0.057). However, other markers of ribosome biogenesis including c-Myc mRNA, Nop56 mRNA, Bop1 mRNA, Ncl mRNA decreased with ORX independently of TEST treatments (P < 0.05). Finally, lower phospho-(Ser235/236)-to-total rps6 protein and lower rpl5 protein levels existed in ORX+TEST rats versus other treatments, suggesting that chronic TEST treatment may lower translational capacity.
authors.affiliation: School of Kinesiology, Auburn University, Auburn, AL, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Mobley
authors.affiliation: School of Kinesiology, Auburn University, Auburn, AL, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Mumford
authors.affiliation: School of Kinesiology, Auburn University, Auburn, AL, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Kephart
authors.affiliation: Research Service, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.
authors.forename: C F
authors.initials: CF
authors.lastname: Conover
authors.affiliation: Research Service, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.|Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Beggs
authors.affiliation: Research Service, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.|Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
authors.forename: A
authors.initials: A
authors.lastname: Balaez
authors.affiliation: Research Service, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.|Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Yarrow
authors.affiliation: Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.|Geriatric Research Education and Clinical Center (GRECC), Department of Veterans Affairs Medical Center, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Borst
authors.affiliation: Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Auburn, AL, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Beck
authors.affiliation: School of Kinesiology, Auburn University, Auburn, AL, USA. mdr0024@auburn.edu.|Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Auburn, AL, USA. mdr0024@auburn.edu.
authors.forename: M D
authors.initials: MD
authors.lastname: Roberts
mesh_terms: D000728:Androgens / Q000494:pharmacology; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D008297:Male; D024510:Muscle Development / Q000187:drug effects; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D009919:Orchiectomy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D000728:Androgens; D015415:Biomarkers; D009124:Muscle Proteins; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; D013739:Testosterone
keywords: Androgen; ribosome biogenesis; testosterone; translational capacity