NUTRITIONAL REGULATION OF CELL AND ORGAN GROWTH, DIFFERENTIATION, AND DEVELOPMENT
Location: Children Nutrition Research Center (Houston, Tx)
Title: Feeding-induced time course of changes in protein synthesis in neonatal pig skeletal muscle
| Wilson, Fiona - |
| Suryawan, Agus - |
| Orellana, Renan - |
| Kimball, Scot - |
| Gazzaneo, Maria - |
| Nguyen, Hanh - |
| Davis, Teresa - |
Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: February 20, 2009
Publication Date: April 2, 2009
Citation: Wilson, F.A., Suryawan, A., Orellana, R.A., Kimball, S.R., Gazzaneo, M.C., Nguyen, H.V., Davis, T.A. 2009. Feeding-induced time course of changes in protein synthesis in neonatal pig skeletal muscle [abstract]. Federation of American Societies for Experimental Biology Conference. Today's Research: Tomorrow's Health. Session: Protein and amino acid metabolism I, April 18-22, 2009, New Orleans, Louisiana. Electronic Abstract 23(1), Abstract No. 738.2.
Feeding increases protein synthesis by promoting translation initiation, and in the neonate, this increase is greatest in skeletal muscle. This study aimed to identify the feeding-induced time course of the changes in protein synthesis and translation factor activation in muscle. Piglets (n=36; 5-7 day old) enterally fed a complete meal were killed 0 (fasting), 30, 60, 90, 120, or 240 min post-feeding. Skeletal muscle protein synthesis reached a maximum 30 min post-feeding, was sustained through 120 min, and returned to baseline by 120 min. The relative proportion of polysomes vs. nonpolysomes increased at 30 min only. Protein kinase B phosphorylation was maximal 30 min after feeding and fell to baseline by 90 min. Phosphorylation of mammalian target of rapamycin, eukaryotic initiation factor (eIF) 4E binding protein (4EBP1), ribosomal protein S6, and eIF4G phosphorylation increased by 30 min, remained elevated to 120 min, and returned to baseline by 240 min. The association of 4EBP1>eIF4E was reduced and eIF4E>eIF4G increased 30 min post-feeding, remained so to 120 min, and then returned to baseline. Feeding rapidly increased neonatal muscle protein synthesis by enhancing translation initiation, and this increase was sustained for at least 120 min after a meal, but returned to baseline by 240 min.