Ribosome biogenesis adaptation in resistance training-induced XXXX skeletal muscle hypertrophy.

@entity1 @entity15080 @entity71842 @entity39057 @entity4910 @entity23815 @entity3013 @entity3470
UNASSIGNED: @entity3013 (RT) has the capacity to increase skeletal muscle mass, which is due in part to transient increases in the rate of muscle protein synthesis during postexercise recovery. The role of ribosome biogenesis in supporting the increased muscle protein synthetic demands is not known. This study examined the effect of both a single acute bout of resistance exercise (RE) and a chronic RT program on the muscle ribosome biogenesis response. Fourteen healthy young @entity1 performed a single bout of RE both before and after 8 wk of chronic RT. Muscle cross-sectional area was increased by 6    4.5% in response to 8 wk of RT. Acute RE-induced activation of the ERK and @entity3470 pathways were similar before and after RT, as assessed by phosphorylation of ERK, @entity23815 , @entity15080 , and S6 ribosomal protein 1 h postexercise. Phosphorylation of @entity71842 was also similarly elevated following both RE sessions. @entity4910 protein levels, which appeared to be regulated at the translational rather than transcriptional level, were acutely increased after RE. @entity39057 was the only protein found to be highly phosphorylated at rest after 8 wk of training. Also, muscle levels of the rRNAs, including the precursor 45S and the mature transcripts (28S, 18S, and 5.8S), were increased in response to RT. We propose that ribosome biogenesis is an important yet overlooked event in RE-induced muscle hypertrophy that warrants further investigation.
