PMID- 24168310
OWN - NLM
STAT- MEDLINE
DCOM- 20140606
LR  - 20211203
IS  - 1943-5681 (Electronic)
IS  - 0002-9645 (Linking)
VI  - 74
IP  - 11
DP  - 2013 Nov
TI  - Effects of advanced age on whole-body protein synthesis and skeletal muscle 
      mechanistic target of rapamycin signaling in horses.
PG  - 1433-42
LID - 10.2460/ajvr.74.11.1433 [doi]
AB  - OBJECTIVE: To determine the effects of advanced age on whole-body protein 
      synthesis and activation of the mechanistic target of rapamycin (mTOR) signaling 
      pathway in skeletal muscle of horses. ANIMALS: Six 22- to 26-year-old (aged) and 
      six 7- to 14-year-old (mature) horses. PROCEDURES: Whole-body protein synthesis 
      was measured with a 2-hour primed constant infusion of (13)C sodium bicarbonate, 
      followed by a 4-hour primed constant infusion of 1-(13)C phenylalanine. After the 
      infusions, a biopsy specimen was obtained from a gluteus medius muscle and 
      activation of protein kinase B (Akt), p70 riboprotein S6 kinase (S6K1), 
      riboprotein S6 (rpS6), and eukaryotic initiation factor 4E binding protein 1 
      (4EBP1) was determined with western immunoblot analysis. For all horses, 
      inflammatory cytokine expression in muscle and blood samples was measured with 
      quantitative real-time PCR analysis. RESULTS: Advanced age had no effect on 
      whole-body protein synthesis or the phosphorylation of Akt, rpS6, and 4EBP1; 
      however, muscle specimens of aged horses had 42% lower phosphorylation of S6K1 
      than did those of mature horses. Aged and mature horses had similar inflammatory 
      cytokine expression in muscle and blood samples. CONCLUSIONS AND CLINICAL 
      RELEVANCE: The lower S6K1 activation for aged horses, compared with that for 
      mature horses, could be indicative of low rates of muscle protein synthesis in 
      aged horses. However, advanced age had no effect on any other indicators of 
      whole-body or muscle protein synthesis or on measures of systemic or muscle 
      inflammation, which suggested that protein metabolism and subsequently 
      requirements may not differ between healthy mature and aged horses.
FAU - Wagner, Ashley L
AU  - Wagner AL
AD  - Department of Animal and Food Sciences, College of Agriculture, and the Center 
      for Muscle Biology, College of Medicine, University of Kentucky, Lexington, KY 
      40546.
FAU - Urschel, Kristine L
AU  - Urschel KL
FAU - Betancourt, Alejandra
AU  - Betancourt A
FAU - Adams, Amanda A
AU  - Adams AA
FAU - Horohov, David W
AU  - Horohov DW
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Am J Vet Res
JT  - American journal of veterinary research
JID - 0375011
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
RN  - W36ZG6FT64 (Sirolimus)
SB  - IM
MH  - Aging
MH  - Animals
MH  - Blotting, Western/veterinary
MH  - Female
MH  - Horses/*physiology
MH  - Male
MH  - Muscle, Skeletal/*metabolism
MH  - Protein Biosynthesis
MH  - Real-Time Polymerase Chain Reaction/veterinary
MH  - *Signal Transduction
MH  - Sirolimus/*metabolism
MH  - TOR Serine-Threonine Kinases/biosynthesis/*genetics
EDAT- 2013/10/31 06:00
MHDA- 2014/06/07 06:00
CRDT- 2013/10/31 06:00
PHST- 2013/10/31 06:00 [entrez]
PHST- 2013/10/31 06:00 [pubmed]
PHST- 2014/06/07 06:00 [medline]
AID - 10.2460/ajvr.74.11.1433 [doi]
PST - ppublish
SO  - Am J Vet Res. 2013 Nov;74(11):1433-42. doi: 10.2460/ajvr.74.11.1433.