Amino Acid Transport after Sprint Exercise and Oral Amino Acids: 90 Board #6 June 1, 9
2016 (English)In: Medicine & Science in Sports & Exercise: Volume 48(5S) Supplement 1, May 2016, p 5, 2016, Vol. 48, no 5 Suppl 1, 5- p.Conference paper (Other academic)
PURPOSE: To study if oral ingestion of essential amino acids (oral EAA) increases the amino acid transporter SNAT2, Akt/mTOR signaling and muscle protein synthesis (MPS) after sprint exercise.
METHODS: 12 healthy subjects performed three 30-s sprints with 20 minutes rest in between. Subjects consumed EAA + maltodextrin solution or flavoured water (placebo) during the sprint exercise up to 15 min after the last sprint in a randomized order with one month interval. In vivo MPS rate was measured using a stable isotope technique. Subject received a stable isotope of phenylalanine (D5-phenylalanine) to label the precursor pool for protein synthesis. Continuous infusion started before the first sprint and was ended 200 min after the last sprint. Two post exercise biopsies (vastus lateralis) were obtained 80 min and 200 min after last sprint. The amount of labelled phenylalanine incorporated into muscle protein over these 2 hours represents the in vivo MPS rate and was expressed as fractional synthesis rate (FSR %) calculated by dividing amount of labelled phenylalanine incorporated during these 2 hours by the amount in the free amino acid (precursor) plasma pool. Biopsies were also analyzed for Akt/mTOR signaling and SNAT2 amino acid transporter by Western blot and for SNAT2 gene expression by real-time PCR. Blood samples were analyzed for amino acids, glucose, lactate, and insulin. Four subjects, involuntary vomiting after exercise during EAA condition, showed a minor increase in plasma leucine and were presented separately.
RESULTS: Non-vomiting subjects (n=8): The expression of the amino acid transporter SNAT2 was higher both at the protein (P<0.05) and the mRNA (P<0.001) level after EEA than after placebo. Fold increase for phosphorylated Akt, mTOR and p70 was 1.7-3.6 (P<0.01 - P<0.001) comparing EAA with placebo. FSR % after EEA was increased by 25 % (P=0.02) compared to placebo. None of these variables were significantly increased in the subjects who vomited.
CONCLUSION: Oral EAA increased MPS after sprint exercise. Enhanced capacity for amino acid transport and subsequent enhanced Akt/mTOR signaling are suggested to mediate the increased MPS.
Place, publisher, year, edition, pages
2016. Vol. 48, no 5 Suppl 1, 5- p.
Sport and Fitness Sciences
Research subject Medicine/Technology
IdentifiersURN: urn:nbn:se:gih:diva-4566DOI: 10.1249/01.mss.0000485021.31770.d3PubMedID: 27584180OAI: oai:DiVA.org:gih-4566DiVA: diva2:971084
American College of Sports Medicine (ACSM) 63rd Annual Meeting, May 31-June 4 2016, Boston