title: Oral N-carbamylglutamate supplementation increases protein synthesis in skeletal muscle of piglets.
abstract: 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.
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX 77030-2600, USA. jfrank@uark.edu
authors.forename: Jason W
authors.initials: JW
authors.lastname: Frank
authors.forename: Jeffery
authors.initials: J
authors.lastname: Escobar
authors.forename: Hanh V
authors.initials: HV
authors.lastname: Nguyen
authors.forename: Scott C
authors.initials: SC
authors.lastname: Jobgen
authors.forename: Wenjuan S
authors.initials: WS
authors.lastname: Jobgen
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Davis
authors.forename: Guoyao
authors.initials: G
authors.lastname: Wu
mesh_terms: D000818:Animals; D000833:Animals, Suckling; D019587:Dietary Supplements; D005260:Female; D005508:Food Deprivation; D005971:Glutamates / Q000008:administration & dosage* / Q000494:pharmacology*; D008297:Male; D009124:Muscle Proteins / Q000096:biosynthesis*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*; D013997:Time Factors; D015430:Weight Gain
chemical_list: D005971:Glutamates; D009124:Muscle Proteins; C006895:N-carbamylglutamate