Abstract

We sought to determine if androgen administration to orchiectomized (ORX) rats affects ribosome biogenesis markers. Ten month-old male Fischer 344 rats (n=10-11/group) were treated for 4 weeks following 2 weeks after ORX/Sham surgery with either: a) ORX + testosterone enanthate (ORX+Test; 7 mg/wk), or b) ORX + trenbolone enanthate (ORX+Tren; 1 mg/wk), a non-5α-reducible, non-aromatizable synthetic testosterone analogue. LABC muscle was removed during necropsy and genes of interest were analyzed using RT-PCR. A trend towards significance existed between groups regarding total RNA/mg wet muscle (p = 0.098), with ORX being 20-23% lower versus other groups. Interestingly, several ribosomal biogenesis markers were greater in SHAM versus other groups (p < 0.001). 5S rRNA and Raptor mRNA were greater in ORX+Tren versus other groups, respectively (p < 0.05). Rpl-3 mRNA was greater in ORX and ORX+Tren versus SHAM (p = 0.048, 0.002), and was also greater in ORX+Test (p < 0.001, 0.02) versus SHAM and ORX. Nucleophosmin mRNA was greater in ORX versus other groups (p < 0.001). ORX suppressed the expression of various ribosomal markers and genes, though androgen treatment largely rescued this effect.