Housová J

The use of microdialysis to characterize the endocrine production of human subcutaneous adipose tissue in vivo.

OBJECTIVE Adipose tissue-derived factors represent important players in the metabolic regulations acting both on systemic and local level. However, their local concentrations in human adipose tissue are poorly described. METHODS We measured 24-hour profile and post-glucose load concentrations of selected adipokines in the subcutaneous adipose tissue of 17 healthy women by in vivo microdialysis. During 24-hour period, subjects consumed two standardized meals (at 13.00 h and at 19.00 h). RESULTS During 24-hour period, fat interleukin-6, interleukin-8/CXCL8, resistin, and hepatocyte growth factor (HGF) exhibited increase/decrease/plateau pattern and peaked at about 14.30 h. Fat leptin exhibited increase/plateau/decrease/increase pattern and reached plateau between 22.00 and 5.30 h. Fat adiponectin exhibited decrease/plateau pattern and reached plateau between 1.00 and 7.00 h. Fat plasminogen activator inhibitor-1 (PAI-1) exhibited decrease/increase pattern with the lowest value at 20.30 h. Oral glucose consumption significantly increased fat adiponectin and resistin levels and decreased fat leptin and PAI-1 levels, respectively. CONCLUSIONS The levels of studied adipokines in subcutaneous fat exhibited significant variations during the 24-hour period after microdialysis catheter insertion that were not reflected in the circulation. Concentrations of adiponectin, resistin, leptin and PAI-1 were regulated by oral glucose ingestion from 1 to 3 h after oral glucose load in healthy women.

Soluble leptin receptor and leptin levels in pregnant women before and after delivery.

Soluble leptin receptor is an extracellular domain of the leptin receptor that serves as the main leptin‐binding protein and may play a role in the regulation of leptin tissue effects. The aim of our study was to assess serum concentrations of leptin, soluble leptin receptor, and other hormones involved in the regulation of leptin secretion in pregnant women before and after delivery. Serum leptin, cortisol, and tumor necrosis factor α (TNF‐α) concentrations in 19 pregnant women before delivery were significantly higher than in healthy nonpregnant women (33.3 ± 21.0 vs. 7.9 ± 3.5 ng/mL, 1068.9 ± 442.2 vs. 546.6 ± 165.3 nmol/L, 4.4 ± 1.1 vs. 3.4 ± 1.2 ng/mL, respectively). In contrast, no differences between these groups were found in soluble leptin receptor levels. Delivery significantly decreased serum leptin and cortisol levels and increased soluble leptin receptor levels (12.3 ± 9.1 ng/mL, 749.6 ± 205.3 nmol/L, 23.3 ± 7.9 U/mL, respectively). Soluble leptin receptor levels after delivery became higher than in the control group. We conclude that serum leptin and serum soluble leptin‐receptor levels are significantly affected by pregnancy and delivery. The regulation of leptin levels in this group of patients appears to be distinct and independent of soluble leptin‐receptor levels.