Related Experiment Video
Updated: May 10, 2026

Development of a Neonatal Piglet Acute Lung Injury Model Recreating the Early Environment of Preterm Infant Lungs
Published on: October 31, 2025
Viscera and muscle protein synthesis in neonatal pigs is increased more by intermittent bolus than by continuous
Samer W El-Kadi1, María C Gazzaneo, Agus Suryawan
1U.S. Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.
Background:
Continuous and intermittent bolus orogastric feedings are strategies used in infants unable to tolerate normal feeds.
Methods:
To determine the effects of feeding modality on protein synthesis in different tissues, neonatal pigs received a balanced formula by orogastric tube as an intermittent bolus feed every 4 h or as a continuous infusion, or were fasted overnight.
Results:
As compared with fasting, protein synthesis in gastrocnemius, masseter, and soleus muscles; left ventricle; liver; pancreas; jejunum; and kidney increased in bolus- and continuously fed pigs, but the greatest increase occurred after a bolus meal. Tuberous sclerosis complex (TSC2), the proline-rich AKT substrate of 40 kDa (PRAS40), eukaryotic initiation factor (eIF) 4E binding protein (4EBP1), and ribosomal protein S6 kinase 1 (S6K1) phosphorylation in all tissues, and the proportion of ribosomal protein S4 in liver polysomes were enhanced 90 min following the bolus meal but not immediately before the meal or during continuous feeding. Eukaryotic elongation factor 2 (eEF2) and eIF2α phosphorylation were unaffected by feeding.
Conclusion:
These results suggest that intermittent bolus feeding increases protein synthesis in muscles of different fiber types and visceral tissues to a greater extent than continuous feeding by stimulating translation initiation.
Related Concept Videos
Drug Accumulation During Multiple Dosing: Intermittent IV Infusions
Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption
Enteral Nutrition II: Nasointestinal and Gastrostomy Feeding
Nasointestinal Feeding
Nasointestinal feeding involves placing a tube through...
Overview of Protein Metabolism
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Drug Accumulation During Multiple Dosing: Repetitive IV Injections

