20 research outputs found
Expression of adiponectin receptors 1 and 2 in the ovary and concentration of plasma adiponectin during the oestrous cycle of the pig
The aim of this study was to compare the expression levels of adiponectin receptor 1 and adiponectin receptor 2 mRNAs and proteins in porcine ovaries during four stages (days 2 to 3, 10 to 12, 14 to 16, 17 to 19) of the oestrous cycle and to measure adiponectin plasma concentrations during the same phases of the cycle. Higher mRNA expression of adiponectin receptor 1 was detected in porcine granulosa cells than in corpora lutea and theca cells (P < 0.01). In contrast, higher gene expression of adiponectin receptor 2 occurred in newly developed and mature corpora lutea (P < 0.01). The adiponectin receptor 1 protein content was the highest in corpora lutea isolated on days 2 to 3 of the cycle and was the lowest in theca interna cells (P < 0.01). The profile of adiponectin receptor 2 protein was similar to that of adiponectin receptor 1. Adiponectin plasma concentrations were significantly higher throughout the luteal phase than in the follicular phase (P < 0.01). In conclusion, the presence of adiponectin receptor 1 and adiponectin receptor 2 mRNAs and proteins in the porcine ovary suggests that adiponectin may directly affect ovarian functions through its own specific receptors. The expression of both receptors and adiponectin plasma concentration were dependent on hormonal status related to the stage of the cycle
Pharmacokinetics of Mephedrone Enantiomers in Whole Blood after a Controlled Intranasal Administration to Healthy Human Volunteers
Mephedrone, which is one of the most popular synthetic cathinones, has one chiral centre and thus exists as two enantiomers: R-(+)-mephedrone and S-(−)-mephedrone. There are some preliminary data suggesting that the enantiomers of mephedrone may display enantioselective pharmacokinetics and exhibit different neurological effects. In this study, enantiomers of mephedrone were resolved via chromatographic chiral recognition and the absolute configuration was unambiguously determined by a combination of elution order and chiroptical analysis (i.e., circular dichroism). A chiral liquid chromatography tandem mass spectrometry method was fully validated and was applied to the analysis of whole blood samples collected from a controlled intranasal administration of racemic mephedrone hydrochloride to healthy male volunteers. Both enantiomers showed similar kinetics, however, R-(+)-mephedrone had a greater mean Cmax of 48.5 ± 11.9 ng/mL and a longer mean half-life of 1.92 ± 0.27 h compared with 44.6 ± 11.8 ng/mL and 1.63 ± 0.23 h for S-(−)-mephedrone, respectively. Moreover, R-(+)-mephedrone had a lower mean clearance and roughly 1.3 times greater mean area under the curve than S-(−)-mephedrone. Significant changes in the enantiomeric ratio over time were observed, which suggest that the analytes exhibit enantioselective pharmacokinetics. Even though the clinical significance of this finding is not yet fully understood, the study confirms that the chiral nature, and consequently the enantiomeric purity of mephedrone, can be a crucial consideration when interpreting toxicological results
Myogenic Differentiation of Mouse Embryonic Stem Cells That Lack a Functional Pax7 Gene
The transcription factor Pax7 plays a key role during embryonic myogenesis and sustains the proper function of
satellite cells, which serve as adult skeletal muscle stem cells. Overexpression of Pax7 has been shown to
promote the myogenic differentiation of pluripotent stem cells. However, the effects of the absence of functional
Pax7 in differentiating embryonic stem cells (ESCs) have not yet been directly tested. Herein, we studied
mouse stem cells that lacked a functional Pax7 gene and characterized the differentiation of these stem cells
under conditions that promoted the derivation of myoblasts in vitro. We analyzed the expression of myogenic
factors, such as myogenic regulatory factors and muscle-specific microRNAs, in wild-type and mutant cells.
Finally, we compared the transcriptome of both types of cells and did not find substantial differences in the
expression of genes related to the regulation of myogenesis. As a result, we showed that the absence of
functional Pax7 does not prevent the in vitro myogenic differentiation of ESCs
Cell cycle regulation of embryonic stem cells and mouse embryonic fibroblasts lacking functional Pax7
The transcription factor Pax7 plays a key role during embryonic myogenesis and in adult organisms in that
it sustains the proper function of satellite cells, which serve as adult skeletal muscle stem cells. Recently
we have shown that lack of Pax7 does not prevent the myogenic differentiation of pluripotent stem cells.
In the current work we show that the absence of functional Pax7 in differentiating embryonic stem cells
modulates cell cycle facilitating their proliferation. Surprisingly, deregulation of Pax7 function also
positively impacts at the proliferation of mouse embryonic fibroblasts. Such phenotypes seem to be
executed by modulating the expression of positive cell cycle regulators, such as cyclin E
Polarographic studies on iron(II) complexes with carbamide derivatives containing alkyl substituents
Dynamic interplay of ParA with the polarity protein, Scy, coordinates growth with chromosome segregation in Streptomyces coelicolor
status: publishe
Detection of mephedrone and its metabolites in fingerprints from a controlled human administration study by liquid chromatography-tandem mass spectrometry and paper spray-mass spectrometry
The use of synthetic stimulants, including designer cathinones, remains a significant concern worldwide.
Thus, the detection and identification of synthetic cathinones in biological matrices is of paramount
importance for clinical and forensic laboratories. In this study, distribution of mephedrone and its metabolites was investigated in fingerprints. Following a controlled human mephedrone administration (100 mg
nasally insufflated), two mass spectrometry-based methods for fingerprint analysis have been evaluated.
The samples deposited on triangular pieces of chromatography paper were directly analysed under
ambient conditions by paper spray-mass spectrometry (PS-MS) while those deposited on glass cover slips
were extracted and analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The
LC-MS/MS method was 5–6 times more sensitive than PS-MS but required sample preparation and
longer analysis time. Mephedrone was detected in 62% and in 38% of all post-administration samples analysed
by LC-MS/MS and PS-MS, respectively. Nor-mephedrone was the only metabolite detected in 3.8%
of all samples analysed by LC-MS/MS. A large inter- and intra-subject variation was observed for mephedrone
which may be due to several factors, such as the applied finger pressure, angle and duration of
contact with the deposition surface and inability to control the ‘amount’ of collected fingerprint deposits.
Until these limitations are addressed, we suggest that the sole use of fingerprints can be a useful diagnostic
tool in qualitative rather than quantitative analysis, and requires a confirmatory analysis in a different
biological matrix
Comparative untargeted metabolomics analysis of the psychostimulants 3,4-methylenedioxy-methamphetamine (MDMA), amphetamine, and the novel psychoactive substance mephedrone after controlled drug administration to humans
Psychoactive stimulants are a popular drug class which are used recreationally. Over the last decade, large numbers of new psychoactive substances (NPS) have entered the drug market and these pose a worldwide problem to human health. Metabolomics approaches are useful tools for simultaneous detection of endogenous metabolites affected by drug use. They allow identification of pathways or characteristic metabolites, which might support the understanding of pharmacological actions or act as indirect biomarkers of consumption behavior or analytical detectability. Herein, we performed a comparative metabolic profiling of three psychoactive stimulant drugs 3,4-methylenedioxymethamphetamine (MDMA), amphetamine and the NPS mephedrone by liquid chromatography-high resolution mass spectrometry (LC-HRMS) in order to identify common pathways or compounds. Plasma samples were obtained from controlled administration studies to humans. Various metabolites were identified as increased or decreased based on drug intake, mainly belonging to energy metabolism, steroid biosynthesis and amino acids. Linoleic acid and pregnenolone-sulfate changed similarly in response to intake of all drugs. Overall, mephedrone produced a profile more similar to that of amphetamine than MDMA in terms of affected energy metabolism. These data can provide the basis for further in-depth targeted metabolome studies on pharmacological actions and search for biomarkers of drug use