Determination of testosterone/epitestosterone concentration ratio in human urine by capillary electrophoresis.

A novel method for determining the testosterone/epitestosterone concentration ratio in human urine was established by capillary electrophoresis with diode-array detector. The urine samples were firstly purified by the solid extraction. The optimal experimental conditions were: running buffer pH = 4.74, 15.0 mmol L-1 HAc-NaAc, separation voltage 25 kV, temperature 25 °C, sample injection pressure 3.43 × 103 Pa, and duration 10 s. The testosterone and epitestosterone linear range were determined as 8.0-960.0 ng mL-1, respectively. The testosterone and epitestosterone detection limits were determined as 4.6 and 4.5 ng mL-1, respectively. The relative standard deviation was less than 0.36%.

Exercise training ameliorates bleomycin-induced epithelial mesenchymal transition and lung fibrosis through restoration of H2 S synthesis.

AIMS: Clinical trials have shown the beneficial effects of exercise training against pulmonary fibrosis. This study aimed to investigate whether prophylactic intervention with exercise training attenuates lung fibrosis via modulating endogenous hydrogen sulphde (H2 S) generation. METHODS: First, ICR mice were allocated to Control, Bleomycin, Exercise, and Bleomycin + Exercise groups. Treadmill exercise began on day 1 and continued for 4 weeks. A single intratracheal dose of bleomycin (3 mg/kg) was administered on day 15. Second, ICR mice were allocated to Control, Bleomycin, H2 S, and Bleomycin + H2 S groups. H2 S donor NaHS (28 µmol/kg) was intraperitoneally injected once daily for 2 weeks. RESULTS: Bleomycin-treated mice exhibited increased levels of collagen deposition, hydroxyproline, collagen I, transforming growth factor (TGF)-ß1, Smad2/Smad3/low-density lipoprotein receptor-related proteins (LRP-6)/glycogen synthase kinase-3ß (GSK-3ß) phosphorylation, and Smad4/ß-catenin expression in lung tissues (P < 0.01), which was alleviated by exercise training (P < 0.01 except for Smad4 and phosphorylated GSK-3ß: P < 0.05). Bleomycin-induced lung fibrosis was associated with increased α smooth muscle actin (α-SMA) and decreased E-cadherin expression (P < 0.01). Double immunofluorescence staining showed the co-localization of E-cadherin/α-SMA, indicating epithelial-mesenchymal transition (EMT) formation, which was ameliorated by exercise training. Moreover, exercise training restored bleomycin-induced downregulation of cystathionine-ß-synthase (CBS) and cystathionine-γ-lyase (CSE) expression, as well as H2 S generation in lung tissue (P < 0.01). NaHS treatment attenuated bleomycin-induced TGF-ß1 production, activation of LRP-6/ß-catenin signalling, EMT and lung fibrosis (P < 0.01 except for ß-catenin: P < 0.05). CONCLUSION: Exercise training restores bleomycin-induced downregulation of pulmonary CBS/CSE expression, thus contributing to the increased H2 S generation and suppression of TGF-ß1/Smad and LRP-6/ß-catenin signalling pathways, EMT and lung fibrosis.