Skip to main content
ARS Home » Plains Area » Houston, Texas » Research » Publications at this Location » Publication #180548
Title: A PHYSIOLOGICAL RISE IN LEUCINE, BUT NOT ISOLEUCINE OR VALINE, INCREASES PROTEIN SYNTHESIS AND TRANSLATION INITIATION FACTOR ACTIVATION IN SKELETAL MUSCLE OF NEONATAL PIGS

Author
item ESCOBAR, JEFFERY - 3092-00-00
item FRANK, JASON - 3092-00-00
item SURYAWAN, AGUS - 3092-00-00
item NGUYEN, HANH - 3092-00-00
item Davis, Teresa

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/19/2005
Publication Date: 4/2/2005
Citation: Escobar, J., Frank, J.W., Suryawan, A., Nguyen, H.V., Davis, T.A. 2005. A physiological rise in leucine, but not isoleucine or valine, increases protein synthesis and translation initiation factor activation in skeletal muscle of neonatal pigs [abstract]. The 2005 Federation of American Societies for Experimental Biology Conference. Part II(abstract 571.3):A976.

Interpretive Summary: Not Required for an Abstract.

Technical Abstract: Protein synthesis in skeletal muscle of neonatal pigs, an anabolic population highly sensitive to amino acids and insulin, increases in response to a physiological increase in plasma leucine. However, the effect of a physiological increase in plasma isoleucine and valine, compared to leucine, on skeletal muscle protein synthesis has not been investigated in neonates. Thus, fasted pigs were infused intra-arterially with leucine, isoleucine or valine (0 or 400 umol•kg[-1]•h[-1]) and protein synthesis was measured after 60 min. Infusion of leucine, but not isoleucine or valine, increased (P<0.05) phosphorylation of eukaryotic initiation factor (eIF) 4E binding protein-1 (4E-BP1), ribosomal protein (rp) S6 kinase (S6K1), and rpS6, and increased the amount of eIF4E associated with eIF4G in longissimus dorsi and masseter muscles. Protein synthesis was increased (P<0.03) in longissimus dorsi and masseter muscles in response to leucine, but not isoleucine or valine. Thus, a physiological rise in plasma leucine, but not isoleucine or valine, stimulates protein synthesis in skeletal muscle of neonatal pigs by increasing eIF4E availability for eIF4F assembly.