title: An in vivo microdialysis characterization of the transient changes in the interstitial dialysate concentration of metabolites and cytokines in human skeletal muscle in response to insertion of a microdialysis probe.
abstract: Skeletal muscle has recently been described as an endocrine organ, capable of releasing cytokines and regulators of metabolism. Microdialysis of the interstitial space of skeletal muscle enables analysis of the release of such cytokines. The purpose of this study was to determine the transient changes in concentration of metabolites and cytokines in human skeletal muscle in a 7h period following the insertion of a microdialysis probe. In total, sixteen microdialysis catheters were inserted into the vastus lateralis of male participants (age 26.2±1.35y, height 180.8±3.89cm, mass 83.9±3.86kg, BMI 25.7±0.87kgm(-2), body fat 26.1±3.0%). Serial samples were analyzed by micro-enzymatic and multiplexed immunoassay. Muscle interstitial glucose and lactate levels remained stable throughout, amino acid concentrations stabilized after 2.5h, however, insertion of a microdialysis catheter induced a 29-fold increase in peak IL-6 (p<0.001) and 35-fold increase in peak IL-8 concentrations (p<0.001) above basal levels 6h post insertion. In contrast to stable amino acid, glucose and lactate concentrations after 2h, commonly reported markers of tissue homeostasis in in vivo microdialysis, the multi-fold increase in IL-6 and IL-8 following insertion of a microdialysis catheter is indicative of a sustained disturbance of tissue homeostasis.
authors.affiliation: Human Science Research Unit, Physical Education and Sport Sciences, Faculty of Education and Health Sciences, University of Limerick, Limerick, Ireland. Electronic address: brian.carson@ul.ie.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Carson
authors.affiliation: Human Science Research Unit, Physical Education and Sport Sciences, Faculty of Education and Health Sciences, University of Limerick, Limerick, Ireland.
authors.forename: William G
authors.initials: WG
authors.lastname: McCormack
authors.affiliation: Human Science Research Unit, Physical Education and Sport Sciences, Faculty of Education and Health Sciences, University of Limerick, Limerick, Ireland.
authors.forename: Clare
authors.initials: C
authors.lastname: Conway
authors.affiliation: Graduate Entry Medical School (GEMS), Faculty of Education and Health Sciences, University of Limerick, Limerick, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Cooke
authors.affiliation: Statistical Consulting Unit, University of Limerick, Limerick, Ireland.
authors.forename: Jean
authors.initials: J
authors.lastname: Saunders
authors.affiliation: Graduate Entry Medical School (GEMS), Faculty of Education and Health Sciences, University of Limerick, Limerick, Ireland.
authors.forename: William T
authors.initials: WT
authors.lastname: O'Connor
authors.affiliation: Human Science Research Unit, Physical Education and Sport Sciences, Faculty of Education and Health Sciences, University of Limerick, Limerick, Ireland.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Jakeman
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000737:chemistry; D015992:Body Mass Index; D002336:Carnosine / Q000737:chemistry; D057785:Catheters; D016207:Cytokines / Q000378:metabolism*; D045604:Extracellular Fluid / Q000378:metabolism*; D005947:Glucose / Q000737:chemistry; D006706:Homeostasis; D006801:Humans; D007118:Immunoassay; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D019344:Lactic Acid / Q000737:chemistry; D008297:Male; D017551:Microdialysis; D018482:Muscle, Skeletal / Q000378:metabolism*; D052097:Quadriceps Muscle / Q000473:pathology; D013654:Taurine / Q000737:chemistry
chemical_list: D000596:Amino Acids; C508606:CXCL8 protein, human; D016207:Cytokines; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D013654:Taurine; D019344:Lactic Acid; D002336:Carnosine; D005947:Glucose
keywords: Cytokine; Interstitium; Microdialysis; Muscle