title: Effects of an amylopectin and chromium complex on the anabolic response to a suboptimal dose of whey protein.
abstract: BACKGROUND
  Previous research has demonstrated the permissive effect of insulin on muscle protein kinetics, and the enhanced insulin sensitizing effect of chromium. In the presence of adequate whole protein and/or essential amino acids (EAA), insulin has a stimulatory effect on muscle protein synthesis, whereas in conditions of lower blood EAA concentrations, insulin has an inhibitory effect on protein breakdown. In this study, we determined the effect of an amylopectin/chromium (ACr) complex on changes in plasma concentrations of EAA, insulin, glucose, and the fractional rate of muscle protein synthesis (FSR).
  
  
  METHODS
  Using a double-blind, cross-over design, ten subjects (six men, four women) consumed 6 g whey protein + 2 g of the amylopectin-chromium complex (WPACr) or 6 g whey protein (WP) after an overnight fast. FSR was measured using a primed, continuous infusion of ring-d5-phenylalanine with serial muscle biopsies performed at 2, 4, and 8 h. Plasma EAA and insulin were assayed by ion-exchange chromatography and ELISA, respectively. After the biopsy at 4 h, subjects ingested their respective supplement, completed eight sets of bilateral isotonic leg extensions at 80% of their estimated 1-RM, and a final biopsy was obtained 4 h later.
  
  
  RESULTS
  Both trials increased EAA similarly, with peak levels noted 30 min after ingestion. Insulin tended (p= 0.09) to be higher in the WPACr trial. Paired samples t-tests using baseline and 4-h post-ingestion FSR data separately for each group revealed significant increases in the WPACr group (+0.0197%/h,p= 0.0004) and no difference in the WP group (+0.01215%/hr,p= 0.23). Independent t-tests confirmed significant (p= 0.045) differences in post-treatment FSR between trials.
  
  
  CONCLUSIONS
  These data indicate that the addition of ACr to a 6 g dose of whey protein (WPACr) increases the FSR response beyond what is seen with a suboptimal dose of whey protein alone.
authors.affiliation: The Center for Applied Health Sciences, Division of Sports Nutrition and Exercise Science, 4302 Allen Road, Suite 120, Stow, OH 44224 USA.
authors.forename: T N
authors.initials: TN
authors.lastname: Ziegenfuss
authors.affiliation: The Center for Applied Health Sciences, Division of Sports Nutrition and Exercise Science, 4302 Allen Road, Suite 120, Stow, OH 44224 USA.
authors.forename: H L
authors.initials: HL
authors.lastname: Lopez
authors.affiliation: The Center for Applied Health Sciences, Division of Sports Nutrition and Exercise Science, 4302 Allen Road, Suite 120, Stow, OH 44224 USA.
authors.forename: A
authors.initials: A
authors.lastname: Kedia
authors.affiliation: The Center for Applied Health Sciences, Division of Sports Nutrition and Exercise Science, 4302 Allen Road, Suite 120, Stow, OH 44224 USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Habowski
authors.affiliation: The Center for Applied Health Sciences, Division of Sports Nutrition and Exercise Science, 4302 Allen Road, Suite 120, Stow, OH 44224 USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Sandrock
authors.affiliation: The Center for Applied Health Sciences, Division of Sports Nutrition and Exercise Science, 4302 Allen Road, Suite 120, Stow, OH 44224 USA.
authors.forename: B
authors.initials: B
authors.lastname: Raub
authors.affiliation: Exercise and Performance Nutrition Laboratory, School of Health Sciences, Lindenwood University, 209 S. Kingshighway St., Charles, MO 63301 USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Kerksick
authors.affiliation: The University of Arkansas for Medical Sciences, 4301 West Markham, Little Rock, AR 72205 USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Ferrando
mesh_terms: D000328:Adult; D000687:Amylopectin / Q000008:administration & dosage* / Q000494:pharmacology; D002857:Chromium / Q000008:administration & dosage* / Q000494:pharmacology; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D064133:Sports Nutritional Physiological Phenomena; D000067816:Whey Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000067816:Whey Proteins; D002857:Chromium; D000687:Amylopectin
keywords: Amino acids; Chromium; Insulin; Insulin sensitivity; Muscle protein synthesis