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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #297895
Title: Anabolic signaling and protein deposition are enhanced by intermittent as compared with continuous feeding in skeletal muscle of neonates

Author
item EL-KADI, SAMER - Children'S Nutrition Research Center (CNRC)
item SURYAWAN, AGUS - Children'S Nutrition Research Center (CNRC)
item GAZZANEO, MARIAC - Children'S Nutrition Research Center (CNRC)
item SRIVASTAVA, NEERAJ - Children'S Nutrition Research Center (CNRC)
item ORELLANA, RENAN - Children'S Nutrition Research Center (CNRC)
item NGUYEN, HANH - Children'S Nutrition Research Center (CNRC)
item LOBLEY, GERALD - University Of Aberdeen
item DAVIS, TERESA - Children'S Nutrition Research Center (CNRC)

Submitted to: American Journal of Physiology - Endocrinology and Metabolism
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2012
Publication Date: 3/1/2012
Citation: El-Kadi, S., Suryawan, A., Gazzaneo, M., Srivastava, N., Orellana, R.A., Nguyen, H.V., Lobley, G.E., Davis, T.A. 2012. Anabolic signaling and protein deposition are enhanced by intermittent as compared with continuous feeding in skeletal muscle of neonates. American Journal of Physiology - Endocrinology and Metabolism. 302:E674-E686.

Interpretive Summary: More than 10 percent of the babies in the United States have a low body weight when they are born. Most of these infants are discharged from the hospital weighing much less than normal and they remain small when they are adults. Therefore, we need to develop better ways to manage their nutrition. Many infants in the hospital are fed through a tube that is placed into their stomach. The food can be provided continuously at a constant flow rate or it can be provided intermittently every few hours in a pattern like meal feeding. No studies have examined the effects of the feeding patterns on muscle growth in early life. Scientists at the Children's Nutrition Research Center in Houston, Texas conducted studies in models that demonstrated that when a milk-based formula is given in a meal feeding pattern, the synthesis of proteins in skeletal muscle increases more than if the formula is infused at a continuous flow rate. These findings are important for pediatric nutrition as they suggest that providing formula using the meal feeding pattern of delivery, compared to a continuous pattern, may enhance weight gain and muscle growth in babies.

Technical Abstract: Orogastric tube feeding is indicated for neonates with impaired ability to ingest and can be administered by intermittent bolus or continuous schedule. Our aim of this study was to determine whether feeding modalities affect muscle protein deposition and to identify mechanisms involved. Neonatal pigs were overnight fasted (FAS) or fed the same amount of food continuously (CON) or intermittently (INT; 7 X 4 h meals) for 29 h. For 8 h, between hours 20 and 28, pigs were infused with [(2)H(5)]phenylalanine and [(2)H(2)]tyrosine, and amino acid (AA) net balances were measured across the hindquarters. Insulin, branched-chain AA, phenylalanine, and tyrosine arterial concentrations and whole-body phenylalanine and tyrosine fluxes were greater for INT after the meal than for CON or FAS. The activation of signaling proteins leading to initiation of mRNA translation, including eukaryotic initiation factor (eIF)4E/eIF4G complex formation in muscle, was enhanced by INT compared with CON feeding or FAS. Signaling proteins of protein degradation were not affected by feeding modalities except for microtubule-associated protein light chain 3-II, which was highest in the FAS. Across the hindquarters, AA net removal increased for INT but not for CON or FAS, with protein deposition greater for INT. This was because protein synthesis increased following feeding for INT but remained unchanged for CON and FAS, whereas there was no change in protein degradation across any dietary treatment. These results suggest that muscle protein accretion in neonates is enhanced with intermittent bolus to a greater extent than continuous feeding, mainly by increased protein synthesis.