Oral N-carbamylglutamate supplementation increases protein synthesis in skeletal muscle of piglets

J Nutr. 2007 Feb;137(2):315-9. doi: 10.1093/jn/137.2.315.


This study investigated the potential mechanisms by which oral supplementation of N-carbamylglutamate (NCG), an analogue of endogenous N-acetylglutamate (an activator of arginine synthesis) increases growth rate in sow-reared piglets. Two piglets of equal body weight (BW) and of the same gender from each lactating sow were allotted to receive oral administration of 0 (control) or 50 mg of NCG/kg BW every 12 h for 7 d. Piglets (n=32; BW=3 kg) were studied in the food-deprived or fed state following the 7 d of treatment. Overnight food-deprived piglets were given NCG or water (control) at time 0 and 60 min. Piglets studied in the fed state were gavage-fed sow's milk with their respective NCG treatment at 0 and 60 min. At 60 min, the piglets were administered a flooding dose of [3H]phenylalanine and killed at 90 min to measure tissue protein synthesis. Piglets treated with NCG gained 28% more weight than control pigs (P<0.001) over the 7-d period. Fed pigs had greater rates of protein synthesis in longissimus dorsi and gastrocnemius muscles and duodenum compared with food-deprived pigs (P<0.001). Absolute protein synthesis rates in longissimus dorsi (P=0.050) and gastrocnemius (P=0.068) muscles were 30 and 21% greater, respectively, in NCG-treated compared with control pigs. Piglets supplemented with NCG also had greater plasma concentrations of arginine and somatotropin than control pigs (P<0.001). The results suggest that oral NCG supplementation increases plasma arginine and somatotropin levels, leading to an increase in growth rate and muscle protein synthesis in nursing piglets.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Animals, Suckling
  • Dietary Supplements*
  • Female
  • Food Deprivation
  • Glutamates / administration & dosage*
  • Glutamates / pharmacology*
  • Male
  • Muscle Proteins / biosynthesis*
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / metabolism*
  • Swine / metabolism*
  • Time Factors
  • Weight Gain


  • Glutamates
  • Muscle Proteins
  • N-carbamylglutamate