Lipolysis in human adipose tissue during exercise: comparison of microdialysis and a-v measurements

TY - JOUR

T1 - Lipolysis in human adipose tissue during exercise

T2 - comparison of microdialysis and a-v measurements

AU - Lange, Kai Henrik Wiborg

AU - Lorentsen, Jeanne

AU - Isaksson, Fredrik

AU - Simonsen, Lene

AU - Bülow, Jens

AU - Kjaer, Michael

PY - 2002/3

Y1 - 2002/3

N2 - Subcutaneous adipose tissue lipolysis was studied in vivo by Fick's arteriovenous (a-v) principle using either calculated (microdialysis) or directly measured (catheterization) adipose tissue venous glycerol concentration. We compared results during steady-state (rest and prolonged continuous exercise), as well as during non-steady-state (onset of exercise and early exercise) experimental settings. Fourteen healthy women [age: 74 +/- 1 (SE) yr] were studied at rest and during 60-min continuous bicycling at 60% of peak O(2) uptake. Calculated and measured subcutaneous abdominal adipose tissue venous glycerol concentrations increased substantially from rest to exercise but were similar both at rest and during later stages of exercise. In contrast, during the initial approximately 40 min of exercise, calculated glycerol concentration was significantly lower (approximately 40%) than measured adipose tissue venous glycerol concentration. Despite several methodological limitations inherent to both techniques, the results strongly suggest that microdialysis and catheterization provide similar estimates of subcutaneous adipose tissue lipolysis in steady-state experimental settings like rest and continuous prolonged exercise. However, during shorter periods of exercise (<40 min), the results from the two techniques may differ quantitatively in the studied subjects. Caution should, therefore, be taken when lipolysis is evaluated, based on results obtained by the two techniques under non-steady-state conditions.

AB - Subcutaneous adipose tissue lipolysis was studied in vivo by Fick's arteriovenous (a-v) principle using either calculated (microdialysis) or directly measured (catheterization) adipose tissue venous glycerol concentration. We compared results during steady-state (rest and prolonged continuous exercise), as well as during non-steady-state (onset of exercise and early exercise) experimental settings. Fourteen healthy women [age: 74 +/- 1 (SE) yr] were studied at rest and during 60-min continuous bicycling at 60% of peak O(2) uptake. Calculated and measured subcutaneous abdominal adipose tissue venous glycerol concentrations increased substantially from rest to exercise but were similar both at rest and during later stages of exercise. In contrast, during the initial approximately 40 min of exercise, calculated glycerol concentration was significantly lower (approximately 40%) than measured adipose tissue venous glycerol concentration. Despite several methodological limitations inherent to both techniques, the results strongly suggest that microdialysis and catheterization provide similar estimates of subcutaneous adipose tissue lipolysis in steady-state experimental settings like rest and continuous prolonged exercise. However, during shorter periods of exercise (<40 min), the results from the two techniques may differ quantitatively in the studied subjects. Caution should, therefore, be taken when lipolysis is evaluated, based on results obtained by the two techniques under non-steady-state conditions.

KW - Abdomen

KW - Adipose Tissue/blood supply

KW - Arteries

KW - Bicycling/physiology

KW - Blood/metabolism

KW - Blood Glucose/analysis

KW - Exercise/physiology

KW - Female

KW - Glycerol/blood

KW - Homeostasis

KW - Humans

KW - Lipolysis

KW - Microdialysis

KW - Osmolar Concentration

KW - Regional Blood Flow

KW - Time Factors

KW - Veins

U2 - 10.1152/japplphysiol.00690.2001

DO - 10.1152/japplphysiol.00690.2001

M3 - Journal article

C2 - 11842072

SN - 8750-7587

VL - 92

SP - 1310

EP - 1316

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

IS - 3

ER -