| Popis: |
Previous in vitro studies have demonstrated significant 11-beta hydroxysteroid dehydrogenase (11 beta-HSD) oxo-reductase activity in visceral, but not subcutaneous adipose stromal cells. We have conducted an in vivo study of the cortisol-cortisone shuttle in subcutaneous abdominal adipose tissue.We measured arteriovenous (A-V) differences in serum cortisol and cortisone across subcutaneous abdominal adipose tissue and forearm muscle in a heterogeneous group of subjects.We studied 34 subjects (male:female = 12:22), age median (interquartile range) 45 (19-65) years, body mass index 32.7 (20.4-77.1) kg m-2, total body fat 34.4 (5.6-119.1) kg.Serum cortisol and cortisone were measured in serum samples from a radial artery, superficial epigastric vein and deep forearm vein. Abdominal adipose and forearm blood flow rates were measured by 133Xenon washout and plethysmography, respectively.For cortisone, there was significant (P0.001) clearance by adipose tissue, with an A-V difference of 4 (1-7) nmol/l. For cortisol there was a trend for arterial concentrations (203 (142-292) nmol/l) to be lower than venous (225 (152-263) nmol/l), but this was not significant. The adipose tissue cortisone clearance rate correlated with total body fat (r = 0.35, P = 0.05).We have demonstrated 11 beta-HSD oxo-reductase activity in subcutaneous abdominal adipose tissue, which may be increased in obesity. |
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