Amino Acids

, Volume 42, Issue 4, pp 1405–1416

Acute regulation of IGF-I by alterations in post-exercise macronutrients

  • E. B. Foster
  • G. Fisher
  • J. L. Sartin
  • T. H. Elsasser
  • G. Wu
  • W. Cowan
  • D. D. Pascoe
Original Article

DOI: 10.1007/s00726-011-0837-y

Cite this article as:
Foster, E.B., Fisher, G., Sartin, J.L. et al. Amino Acids (2012) 42: 1405. doi:10.1007/s00726-011-0837-y

Abstract

This investigation sought to examine the contributions of exercise and nutrient replenishment on in vivo regulation of the insulin-like growth factor-I (IGF-I) axis components. Eight college-aged males completed three high-intensity interval training (HIIT) protocols followed by three post-exercise nutritional protocols: (1) placebo (EX); (2) carbohydrate only (CHO); and (3) essential amino acid/carbohydrate (EAA/CHO). Samples were analyzed for growth hormone (GH), free IGF-I, IGFBP-1, IGFBP-2, insulin, hematocrit, hemoglobin, serum leucine, matrix metalloproteinase-9 (MMP-9) proteolytic activity, and presence of IGFBP-3 protease activity. No evidence for IGFBP-3 proteolysis was observed. Significant increases in [free IGF-I] and [leucine] were observed in the EAA/CHO group only. Significant differences were noted in [IGFBP-1] and [IGFBP-2] across conditions. Significant increases in [GH] and MMP-9 activity were observed in all groups. These results indicate that post-exercise macronutrient ratio is a determinant of [free IGF-I], [IGFBP-1 and -2] and may play a role in modulating the IGF-I axis in vivo.

Keywords

IGF-IHIITIGFBPEAA

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • E. B. Foster
    • 1
  • G. Fisher
    • 1
  • J. L. Sartin
    • 2
  • T. H. Elsasser
    • 3
  • G. Wu
    • 4
    • 5
  • W. Cowan
    • 6
  • D. D. Pascoe
    • 1
  1. 1.Department of KinesiologyAuburn UniversityAuburnUSA
  2. 2.Department of Anatomy, Physiology, and PharmacologyCollege of Veterinary Medicine, Auburn UniversityAuburnUSA
  3. 3.Bovine Functional Genomics Laboratory, Agricultural Research ServiceU.S. Department of AgricultureBeltsvilleUSA
  4. 4.Cardiovascular Research Institute, Department of Systems Biology and Translational MedicineTexas A&M Health Science CenterCollege StationUSA
  5. 5.Department of Animal ScienceTexas A&M UniversityCollege StationUSA
  6. 6.Department of Health and Physical EducationAthens State UniversityAthensUSA