title: Betaine supplementation enhances anabolic endocrine and Akt signaling in response to acute bouts of exercise.
abstract: Our aim was to examine the effect of betaine supplementation on selected circulating hormonal measures and Akt muscle signaling proteins after an acute exercise session. Twelve trained men (age 19.7 ± 1.23 years) underwent 2 weeks of supplementation with either betaine (B) (1.25 g BID) or placebo (P). Following a 2-week washout period, subjects underwent supplementation with the other treatment (B or P). Before and after each 2-week period, subjects performed an acute exercise session (AES). Circulating GH, IGF-1, cortisol, and insulin were measured. Vastus lateralis samples were analyzed for signaling proteins (Akt, p70 S6k, AMPK). B (vs. P) supplementation approached a significant increase in GH (mean ± SD (Area under the curve, AUC), B: 40.72 ± 6.14, P: 38.28 ± 5.54, p = 0.060) and significantly increased IGF-1 (mean ± SD (AUC), B: 106.19 ± 13.45, P: 95.10 ± 14.23, p = 0.010), but significantly decreased cortisol (mean ± SD (AUC), B: 1,079.18 ± 110.02, P: 1,228.53 ± 130.32, p = 0.007). There was no difference in insulin (AUC). B increased resting Total muscle Akt (p = 0.003). B potentiated phosphorylation (relative to P) of Akt (Ser(473)) and p70 S6 k (Thr(389)) (p = 0.016 and p = 0.005, respectively). Phosphorylation of AMPK (Thr(172)) decreased during both treatments (both p = 0.001). Betaine (vs. placebo) supplementation enhanced both the anabolic endocrine profile and the corresponding anabolic signaling environment, suggesting increased protein synthesis.
authors.affiliation: Human Performance Laboratory, Department of Kinesiology, University of Connecticut, 2095 Hillside Road, Unit 1110, Storrs, CT 06269, USA.
authors.forename: Jenna M
authors.initials: JM
authors.lastname: Apicella
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Lee
authors.forename: Brooke L
authors.initials: BL
authors.lastname: Bailey
authors.forename: Catherine
authors.initials: C
authors.lastname: Saenz
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Anderson
authors.forename: Stuart A S
authors.initials: SA
authors.lastname: Craig
authors.forename: William J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Volek
authors.forename: Carl M
authors.initials: CM
authors.lastname: Maresh
mesh_terms: D000293:Adolescent; D000328:Adult; D001622:Betaine / Q000008:administration & dosage*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D004703:Endocrine System / Q000187:drug effects* / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005765:Gastrointestinal Agents / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008660:Metabolism / Q000187:drug effects*; D005082:Physical Exertion / Q000187:drug effects / Q000502:physiology; D010919:Placebos; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D055815:Young Adult
chemical_list: D005765:Gastrointestinal Agents; D010919:Placebos; D001622:Betaine; D051057:Proto-Oncogene Proteins c-akt