Leucine stimulation of skeletal muscle protein synthesis
Previous work in this laboratory has demonstrated a stimulatory effect of leucine on skeletal muscle protein synthesis measured in vitro during catabolic conditions. Studies in other laboratories have consistently found this effect in diaphragm muscle, however, studies examining effects on nitrogen balance or with in vivo protein synthesis in skeletal muscle are equivocal. This experiment was designed to determine the potential of leucine to stimulate skeletal muscle protein synthesis in vivo. Male Sprague-Dawley rats weighing 200 g were fasted for 12 hrs, anesthetized, a jugular cannula inserted, and protein synthesis measured using a primed continuous infusion of /sup 14/C-tyrosine. A plateau in specific activity was reached after 30 to 60 min and maintained for 3 hrs. The leucine dose consisted of a 240 umole priming dose followed by a continuous infusion of 160 umoles/hr. Leucine infusion stimulated protein synthesis in the soleus muscle (28%) and in the red (28%) and white portions (12%) of the gastrocnemius muscle compared with controls infused with only tyrosine. The increased rates of protein synthesis were due to increased incorporation of tyrosine into protein and to decreased specific activity of the free tyrosine pool. These data indicate that infusion of leucine has the potential to stimulate in vivo protein synthesis in skeletal muscles.
- Research Organization:
- Univ. of Illinois, Urbana
- OSTI ID:
- 5463532
- Report Number(s):
- CONF-8604222-; TRN: 86-028313
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LEUCINE
BIOLOGICAL EFFECTS
PROTEINS
BIOSYNTHESIS
CARBON 14 COMPOUNDS
IN VIVO
MUSCLES
RATS
TRACER TECHNIQUES
TYROSINE
AMINO ACIDS
ANIMALS
CARBOXYLIC ACIDS
HYDROXY ACIDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
RODENTS
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques