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

• Published in: Amino acids Vol. 42; no. 4; pp. 1405 - 1416
• Main Authors: Foster, E. B., Fisher, G., Sartin, J. L., Elsasser, T. H., Wu, G., Cowan, W., Pascoe, D. D.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01-04-2012; Springer Nature B.V
• Subjects: Adult; Amino acids; Amino Acids, Essential - metabolism; Analytical Chemistry; Biochemical Engineering; Biochemistry; Biocompatibility; Biomedical and Life Sciences; Biomedical materials; Carbohydrate Metabolism; Carbohydrates; Dietary Supplements - analysis; Dietary Supplements - utilization; Exercise; Gene Expression Regulation; Growth Hormone - blood; Humans; In vivo testing; In vivo tests; Insulin - blood; Insulin-Like Growth Factor Binding Protein 1 - blood; Insulin-Like Growth Factor Binding Protein 2 - blood; Insulin-Like Growth Factor I - genetics; Insulin-Like Growth Factor I - metabolism; Leucine; Life Sciences; Male; Neurobiology; Original Article; Proteomics; Surgical implants; Young Adult; IGFBP; IGF-I; EAA; HIIT
• ISSN: 0939-4451; 1438-2199
• DOI: 10.1007/s00726-011-0837-y

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.