Microdialysis-Assessed Exercised Muscle Reveals Localized and Differential IGFBP Responses to Unilateral Stretch Shortening Cycle Exercise

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RESEARCH PRODUCT

Microdialysis-Assessed Exercised Muscle Reveals Localized and Differential IGFBP Responses to Unilateral Stretch Shortening Cycle Exercise

Bradley C. Nindl Bradley C. Nindl Bradley C. Nindl Juha P. Ahtiainen Sheila S. Gagnon Ritva S. Taipale Joseph R. Pierce Joseph R. Pierce Brian J. Martin Meaghan E. Beckner M. Lehti Keijo Häkkinen Heikki Kyröläinen

subject

Adult Male 0301 basic medicine medicine.medical_specialty Microdialysis microdialysis muscle interstitial fluid Antecubital vein Endocrinology Diabetes and Metabolism lihakset 030209 endocrinology & metabolism medicine.disease_cause lcsh:Diseases of the endocrine glands. Clinical endocrinology Stretch shortening cycle Young Adult 03 medical and health sciences Endocrinology 0302 clinical medicine Jumping Interstitial fluid Muscle Stretching Exercises Internal medicine medicine Humans Insulin-Like Growth Factor I Muscle Skeletal lihassolut Original Research lcsh:RC648-665 business.industry endokrinologia Repeated measures design Differential regulation IGF-I Insulin-Like Growth Factor Binding Proteins 030104 developmental biology Endocrinology Stretch-Shortening Cycle Exercise voimaharjoittelu stretch shortening cycle exercise binding proteins business

description

Microdialysis allows for a preview into local muscle metabolism and can provide physiological insight that blood measurements cannot. Purpose: To examine the potential differential IGF-I system regulation in interstitial fluid during unilateral stretch shortening cycle exercise. Methods: 10 men (26 ± 7 year) performed unilateral jumping [stretch shortening cycle (SSC) exercise at 50% of optimal jump height] until volitional fatigue on a sled apparatus. Biological sampling took place using a catheter inserted into an antecubital vein (serum), and 100 kDa microdialysis probes inserted into the thigh muscle of each exercise/control leg (dialysate). Serum was drawn before (Pre; −3 h) and after SSC [Post I (+0 h), II (+3 h), or III (+20 h)]; dialysate was sampled for 2 h before (Pre), during/immediately after (Ex), and 3 h into recovery (Rec) following SSC. IGF-I system parameters (free/total IGF-I and IGFBPs 1–6) were measured with immunoassays. Interstitial free IGF-I was estimated from dialysate IGF-I and relative recovery (ethanol) correction. Data were analyzed with repeated measures ANOVA. Results: Serum total IGF-I remained elevated +3 h (Post II: 182.8 ± 37.6 vs. Pre: 168.3 ± 35.0 ng/mL, p 0.05). Dialysate BP-1 remained increased in both exercise and control legs through 3 h into recovery (Rec vs. Pre, p < 0.01). Dialysate BP-3 also demonstrated a prolonged elevation over Pre SSC concentrations, but in the exercise leg only (Ex and Rec vs. Pre, p < 0.04). We observed a prolonged decrease in dialysate BP-5 (Ex and Rec vs. Pre, p < 0.03) and an increase in BP-4 IP in the exercise leg only. There were no changes relative to Pre SSC in dialysate BP-2 or −6. Conclusions: Unilateral exercise drives differential regulation of the IGF-I system at both local and systemic levels. More specifically, this is the first study to demonstrate that localized exercise increases IGFBP-3, IGFBP-4 and decreases in IGFBP-5 in muscle interstitial fluid. peerReviewed

year	journal	country	edition	language
2020-05-01	Frontiers in Endocrinology

10.3389/fendo.2020.00315 http://dx.doi.org/10.3389/fendo.2020.00315