ABSTRACT
Endurance exercise induces notable acute hormonal responses on the gonadal and adrenal hormones. The purpose of this study was to assess the changes in salivary testosterone (Ts), salivary cortisol (Cs) and T/C ratio during long-distance triathlon. Ten well-trained male triathletes participated in the study and were assessed for hormonal changes at four time-points (pre-competition, post-swimming, post-cycling, and post-running phases). Ts decreased from pre-competition to post-swimming (from 93.37 pg/mL to 57.63 pg/mL; p < .01) and increased during two other parts of the competition to almost pre-competition values (cycling: 79.20 pg/mL, p = .02; running: 89,66 pg/mL, p = .04, respectively). Cs showed a similar behaviour; decreasing in the post-swimming phase (1.74 pg/mL) and increasing in the other transitions (post-cycling: 7.30 pg/mL; post-running: 13.31 pg/mL), with significant differences between pre-competition and post- competition values (p = .01). Conversely, T/C increased significantly from pre-competition to post-swimming phase (p = .04) to later decrease until the end of the competition. Overall, T/C significantly decreased (p < .05). In conclusion, during an Ironman triathlon, hormone values fluctuate in response to the demands of the competition. Ts and Cs decrease after-swimming, increase after-cycling and reach the maximum values after-running. T/C reflects overall catabolic status.
Subject(s)
Hydrocortisone , Running , Bicycling/physiology , Humans , Male , Physical Endurance/physiology , Running/physiology , Swimming/physiology , TestosteroneABSTRACT
In order to understand the intracellular delivery of drugs and to improve the cell killing efficiency of photosensitizers (PSs) used in photodynamic therapy (PDT), we prepared TyroSphere nanoparticles, which are triblock polymer [poly(ethylene glycol)-block-oligo(desaminotyrosyltyrosine octyl ester suberate)-block-poly(ethylene glycol)] aggregates, loaded with amphiphilic porphyrins with either positive (CisDiMPyP) or negative (TPPS2a) charges. Their physicochemical and photochemical properties were investigated, as well as the efficiency and mechanism of PDT death in a cervical cancer cell line (HeLa). The photophysical properties of both PSs were improved when loaded in the nanocarrier, with a decrease in aggregation as well as an increase in the yield of singlet oxygen generation. The physical and chemical stability of TyroSphere nanoparticles allows them to enter cells and to promote the slow intracellular delivery of part of the PSs. Confocal steady-state and lifetime-resolved fluorescence imaging microscopy data showed that the released PSs are free to target their natural intracellular targets, which are mitochondria and lysosomes for CisDiMPyP and TPPS2a, respectively. The photodynamic efficiency of cell killing was increased considerably compared with the free PSs (â¼3×), but the mechanism of cell death was the same as that of the free PSs, which are acute necro-apoptosis for CisDiMPyP and autophagy malfunction for TPPS2a, reflecting the specific damage in mitochondria and lysosomes, respectively. We are confident that TyroSpheres provide a novel and efficient platform to administrate PDT photosensitizers, as well as other drugs with intracellular targets.
Subject(s)
Drug Carriers/chemistry , Oxidants/administration & dosage , Oxidants/chemistry , Pharmaceutical Preparations/administration & dosage , Pharmaceutical Preparations/chemistry , Polymers/chemistry , Porphyrins/chemistry , Apoptosis/drug effects , Cell Line, Tumor , Cell Survival/drug effects , HeLa Cells , Humans , Lysosomes/drug effects , Mitochondria/drug effects , Nanoparticles/chemistry , Photochemotherapy/methods , Photosensitizing Agents/chemistry , Polyethylene Glycols/chemistry , Singlet Oxygen/chemistryABSTRACT
The modABC operon of phytopathogen Xanthomonas axonopodis pv. citri (X. citri) encodes a putative ABC transporter involved in the uptake of the molybdate and tungstate anions. Sequence analyses showed high similarity values of ModA orthologs found in X. campestris pv. campestris (X. campestris) and Escherichia coli. The X. citri modA gene was cloned in pET28a and the recombinant protein, expressed in the E. coli BL21 (DE3) strain, purified by immobilized metal affinity chromatography. The purified protein remained soluble and specifically bound molybdate and tungstate with K(d) 0.29+/-0.12 microM and 0.58+/-0.14 microM, respectively. Additionally binding of molybdate drastically enhanced the thermal stability of the recombinant ModA as compared to the apoprotein. This is the first characterization of a ModA ortholog expressed by a phytopathogen and represents an important tool for functional, biochemical and structural analyses of molybdate transport in Xanthomonas species.
