title: Metabolite levels in human skeletal muscle and adipose tissue studied with microdialysis at low perfusion flow.
abstract: To identify a perfusion flow at which the interstitial fluid completely equilibrates with the microdialysis perfusion fluid, a protocol with successively lower perfusion flows was used. A colloid was included in the perfusion fluid to make sampling possible at the lowest perfusion flows. At 0.16 microliter/min, the measured metabolites had reached a complete equilibration in both tissues, and the measured concentrations of glucose, glycerol, and urea were in good agreement with expected tissue-specific levels. The glucose concentration in adipose tissue (4.98 +/- 0.14 mM) was equal to that of plasma (5.07 +/- 0.07 mM), whereas the concentration in muscle (4.41 +/- 0.11 mM) was lower than in plasma and adipose tissue (P < 0.001). The concentration of lactate was higher (P < 0.001) in muscle (2.39 +/- 0.22 mM) than in adipose tissue (1.30 +/- 0.12 mM), whereas the glycerol concentration in adipose tissue (233 +/- 19.7 microM) was higher (P < 0.001) than in muscle (40.8 +/- 3.0 microM) and in plasma (68.7 +/- 3.97 microM). The concentration of urea was equal in the two tissues. Overall, the study indicates that microdialysis at a low perfusion flow may be a tool to continuously monitor tissue interstitial concentrations.
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Rosdahl
authors.forename: K
authors.initials: K
authors.lastname: Hamrin
authors.forename: U
authors.initials: U
authors.lastname: Ungerstedt
authors.forename: J
authors.initials: J
authors.lastname: Henriksson
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D000431:Ethanol / Q000493:pharmacokinetics; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D018482:Muscle, Skeletal / Q000378:metabolism*; D010477:Perfusion / Q000379:methods; D014508:Urea / Q000097:blood / Q000378:metabolism; D014680:Veins
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid; D000431:Ethanol; D014508:Urea; D005947:Glucose; D005990:Glycerol