| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Pediatrics, United States Department of Agriculture/Agriculture Research Service, Children's Nutrition Research Center, Houston, TX, USA
2 Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA, USA
* To whom correspondence should be addressed. E-mail: tdavis{at}bcm.tmc.edu.
Protein synthesis and eukaryotic initiation factor (eIF) activation are increased in muscle and liver of pigs parenterally infused with amino acids and insulin. To examine the effects of enteral protein and carbohydrate on protein synthesis, pigs (n = 42; BW = 1.7 kg) were fed isocaloric milk diets containing three levels of protein (5, 15, and 25 g.kg BW-1. d-1) and two levels of lactose (Low = 11 and High = 23 g.kg BW-1.d-1) from 1 to 6 d of age. On d 7, pigs were gavage-fed following 4 h food deprivation and tissue protein synthesis rates and biomarkers of mRNA translation were assessed. Piglet growth and protein synthesis rates in muscle and liver increased with dietary protein and plateaued at 15 g.kg BW-1.d-1 (P < 0.001). Growth tended to be greater in High lactose fed pigs (P = 0.07). Plasma insulin was lowest in pigs fed 5 g.kg BW-1 .d-1 protein (P < 0.0001). Plasma branched-chain amino acids increased as protein intake increased (P < 0.0001). Muscle (P < 0.001) and liver (P 
0.001) ribosomal protein S6 kinase (S6K1) and eIF4E binding protein (4E-BP1) phosphorylation increased with protein intake and plateaued at 15 g.kg BW-1.d-1. The results indicate growth and protein synthesis rates in neonatal pigs are influenced by dietary protein and lactose intake, and may be mediated by plasma amino acids and insulin levels. However, feeding protein well above the piglet's requirement does not further stimulate the activation of translation initiation or protein synthesis in skeletal muscle and liver.
This article has been cited by other articles:
|
|
 |
|
  F. A. Wilson, A. Suryawan, R. A. Orellana, S. R. Kimball, M. C. Gazzaneo, H. V. Nguyen, M. L. Fiorotto, and T. A. Davis Feeding Rapidly Stimulates Protein Synthesis in Skeletal Muscle of Neonatal Pigs by Enhancing Translation Initiation J. Nutr., October 1, 2009; 139(10): 1873 - 1880. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Suryawan, A. S. Jeyapalan, R. A. Orellana, F. A. Wilson, H. V. Nguyen, and T. A. Davis Leucine stimulates protein synthesis in skeletal muscle of neonatal pigs by enhancing mTORC1 activation Am J Physiol Endocrinol Metab, October 1, 2008; 295(4): E868 - E875. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A. Wilson, A. Suryawan, R. A. Orellana, H. V. Nguyen, A. S. Jeyapalan, M. C. Gazzaneo, and T. A. Davis Fed levels of amino acids are required for the somatotropin-induced increase in muscle protein synthesis Am J Physiol Endocrinol Metab, October 1, 2008; 295(4): E876 - E883. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A. Wilson, R. A. Orellana, A. Suryawan, H. V. Nguyen, A. S. Jeyapalan, J. Frank, and T. A. Davis Stimulation of muscle protein synthesis by somatotropin in pigs is independent of the somatotropin-induced increase in circulating insulin Am J Physiol Endocrinol Metab, July 1, 2008; 295(1): E187 - E194. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
