Age-related changes in protein synthesis measured in vivo in rat liver and gastrocnemius muscle.
This study analyses in detail the effects of ageing on gastrocnemius muscle and liver protein synthesis measured in vivo at three ages, 1.5 months (young), 12 months (adult) and 24 months (old) in Sprague-Dawley rats. Comparing adult and old rats, muscle protein synthesis was decreased in old rats when expressed per unit of RNA and per day (translational efficiency), was unchanged when expressed in absolute terms and increased when expressed in fractional terms as a result of protein loss due to muscle atrophy. In the liver, only translational efficiency tended to decrease in old rats compared to adult rats. It is concluded that the decline in protein turnover described in vitro is consistent with a decrease in translational efficiency, but that absolute synthesis rates are maintained during ageing. Muscle atrophy is unlikely to result from alterations in protein synthesis pathways.
Mosoni
L
L
Laboratoire d'Etude du Métabolisme Azoté, Centre de Clermont-Ferrand-Theix, Ceyrat, France.
Patureau Mirand
P
P
Houlier
M L
ML
Arnal
M
M
D000375:Aging / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D008099:Liver / Q000378:metabolism*; D008297:Male; D009124:Muscle Proteins / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D012313:RNA / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
D009124:Muscle Proteins; D012313:RNA