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Leandro H Manfredi, D Lustrino, Juliano Machado, Wilian Assis Silveira, Neusa Maria Zanon, Luiz C Navegantes, Isis do Carmo Kettelhut
Previous studies have shown that catecholamines in vivo and in vitro inhibit the activity of Ca(2+)-dependent proteolysis in skeletal muscles under basal conditions. In the present study we sought to investigate the role of catecholamines in regulating the Ca(2+)-dependent proteolysis in soleus and extensor digitorum longus (EDL) muscles from rats acutely exposed to cold. Overall proteolysis, the activity of proteolytic systems as well as protein levels and gene expression of different components of calpain system were investigated in rats submitted to adrenodemedullation (ADMX) and exposed to cold for 24 h...
October 20, 2016: Journal of Applied Physiology
Luigi Giannetti, Giovanni Ferretti, Valentina Gallo, Francesco Necci, Andrea Giorgi, Francesca Marini, Elisa Gennuso, Bruno Neri
Beta-sympathomimetic compounds are widely used in therapy because of the bronchodilator, smooth muscle-relaxant and tocolytic properties. However, their growth promoting and performance enhancing effects are often subject to illegal use. The present work describes the development of a fast and reliable analytical multiresidue method for the confirmation 20 β-agonist compounds in animal hair. The procedure is based on alkaline digestion, LLE with organic solvents, SPE clean up and liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis, and is suitable for the public Official control of β-agonist residues in hair sample...
September 28, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Maria Kristina Parr, Marco H Blokland, Franz Liebetrau, Alexander H Schmidt, Thijs Meijer, Mijo Stanic, Dorota Kwiatkowska, Emilia Waraksa, Saskia S Sterk
The differentiation of clenbuterol abuse and unintentional ingestion by contaminated meat is crucial with respect to the valuation of an adverse analytical finding in human sports doping control. The proportion of the two enantiomers of clenbuterol may serve as potential discriminating parameter. For the determination of the individual enantiomers, specific methods were developed and validated for the different matrices under investigation based on chiral chromatography coupled to tandem mass spectrometry. Data from the administration of clenbuterol from a pharmaceutical preparation and from cattle meat and liver containing residues to humans are presented...
October 3, 2016: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Pengqi Guo, Zhimin Luo, Xinya Xu, Yulan Zhou, Bilin Zhang, Ruimiao Chang, Wei Du, Chun Chang, Qiang Fu
A novel method coupling molecular imprinted monolithic column with two-dimensional liquid chromatography was developed and validated for the analysis of clenbuterol in pork liver and swine urine samples. The polymers were characterized by using Fourier transform infrared spectroscopy, nitrogen adsorption desorption analyses, frontal analysis and the adsorption of selectivity. The results indicated that the imprinted columns were well prepared and possessed high selectivity adsorption capacity. Subsequently, the MIMC-2D-LC (molecular imprinted monolithic column-two dimensional liquid chromatography) method was developed for the selective analysis of clenbuterol in practical samples...
February 15, 2017: Food Chemistry
Jie Cheng, Xiao-Ou Su, Shi Wang, Yiping Zhao
Combining surface-enhanced Raman spectroscopy (SERS) of aggregated graphene oxide/gold nanoparticle hybrids with immunomagnetic bead sample preparation method, a highly sensitive strategy to determine the clenbuterol content in animal urine was developed. Based on a linear calibration curve of the SERS characteristic peak intensity of clenbuterol at Δv = 1474 cm(-1) versus the spiked clenbuterol concentration in the range of 0.5-20 ng·mL(-1), the quantity of clenbuterol in real animal urine samples can be determined and matches well with those determined by LC-MS/MS, while the detection time is significantly reduced to 15 min/sample...
2016: Scientific Reports
Benjamin P Woodall, Meryl C Woodall, Timothy S Luongo, Laurel A Grisanti, Douglas G Tilley, John W Elrod, Walter J Koch
GRK2, a G protein-coupled receptor kinase, plays a critical role in cardiac physiology. Adrenergic receptors are the primary target for GRK2 activity in the heart; phosphorylation by GRK2 leads to desensitization of these receptors. As such, levels of GRK2 activity in the heart directly correlate with cardiac contractile function. Furthermore, increased expression of GRK2 after cardiac insult exacerbates injury and speeds progression to heart failure. Despite the importance of this kinase in both the physiology and pathophysiology of the heart, relatively little is known about the role of GRK2 in skeletal muscle function and disease...
October 14, 2016: Journal of Biological Chemistry
Reem Alshaman, Luan Truong, Adebayo Oyekan
Despite the presence of many studies on the role of mechanistic target of rapamycin (mTOR) in cardiorenal tissues, the definitive role of mTOR in the pathogenesis of renal injury subsequent to ischemia-reperfusion (IR) remains unclear. The aims of the current study were to characterize the role of mTOR in normal kidney function and to investigate the role of mTOR activation in IR-induced kidney injury. In euvolemic anesthetized rats, treatment with the mTOR inhibitor rapamycin increased blood pressure (121±2 to 144±3 mmHg; P<0...
August 24, 2016: Clinical and Experimental Pharmacology & Physiology
Heather K Knych, Linda M Harrison, Stacy J Steinmetz, Nadira Chouicha, Phil H Kass
BACKGROUND: Clenbuterol, a beta2-adrenergic receptor agonist, is used therapeutically to treat respiratory conditions in the horse. However, by virtue of its mechanism of action it has been suggested that clenbuterol may also have repartitioning affects in horses and as such the potential to affect performance. Clenbuterol decreases the percent fat and increases fat-free mass following high dose administration in combination with intense exercise in horses. In the current study, microarray analysis and real-time PCR were used to study the temporal effects of low and high dose chronic clenbuterol administration on differential gene expression of several skeletal muscle myosin heavy chains, genes involved in lipid metabolism and the β2-adrenergic receptor...
2016: BMC Genomics
Haibo Liu, Ning Gan, Yinji Chen, Qingqing Ding, Jie Huang, Saichai Lin, Yuting Cao, Tianhua Li
A quick and specific pretreatment method based on a series of extraction clean-up disks, consisting of molecularly imprinted polymer monoliths and C18 adsorbent, was developed for the specific enrichment of salbutamol and clenbuterol residues in food. The molecularly imprinted monolithic polymer disk was synthesized using salbutamol as a template through a one-step synthesis process. It can simultaneously and specifically recognize salbutamol and clenbuterol. The monolithic polymer disk and series of C18 disks were assembled with a syringe to form a set of tailor-made devices for the extraction of target molecules...
September 2016: Journal of Separation Science
Sena Caglar Andac
A fully automated and validated 2D online solid-phase extraction (SPE) high-performance liquid chromatographic method was described for the direct simultaneous determination of clenbuterol (CLEN) and doxazosin (DOX) in spiked human plasma samples. Chromatographic separation of the analytes was achieved by column-switching. SPE column packed with restricted access material for depleting matrix and a reversed phase HPLC column for eluting analytes were used with UV detection on 250 nm. A 10 mM acetate buffer (pH: 4) and acetonitrile mixture was used in gradient elution with 1 mL/min flow rate, as mass spectrometry friendly mobile phase...
July 19, 2016: Journal of Chromatographic Science
Michelle A Hieger, Michael P Emswiler, Kevin F Maskell, John T Sentz, Kristin B Miller, Carl E Wolf, Kirk L Cumpston, Brandon K Wills
BACKGROUND: Adulteration of drugs of abuse may be done to increase profits. Some adulterants are relatively innocuous and others result in significant toxicity. Clenbuterol is a β2-adrenergic agonist with veterinary uses that has not been approved by the U.S. Food and Drug Administration for human use. It is an infrequently reported heroin adulterant. We describe a cluster of hospitalized patients with laboratory-confirmed clenbuterol exposure resulting in serious clinical effects. CASE SERIES: Ten patients presented with unexpected symptoms shortly after heroin use...
September 2016: Journal of Emergency Medicine
Yeli Luo, Xin Liu, Jiajia Guo, Hanting Gao, Ying Li, Jingyue Xu, Fei Shen, Chunyan Sun
In this paper, a sensitive method for the colorimetric detection of clenbuterol and ractopamine using citrate-stabilized gold nanoparticles (AuNPs) as probe was developed. The concentration of clenbuterol and ractopamine could be determined with naked eyes or a UV-vis spectrometer. By optimizing the influence of NaHSO₄ and incubation time, clenbuterol could be detected in the linear range of 0.1-4 µg/mL with the detection limit of 0.0158 µg/mL, and ractopamine could be detected in the linear range of 1-9 µg/mL with the detection limit of 0...
January 2016: Journal of Nanoscience and Nanotechnology
Juan Li, Qingdong Qiao, Jingxin Zhuang, Cuiping Wang
An analytical method was developed to simultaneously determine the residues of four β2-agonists in animal foods by high performance liquid chromatography/electrospray-tandem mass spectrometry (HPLC-MS/MS). Samples were extracted with 5% (mass fraction) trichloracetic acid, and then cleaned up by two solid phase extraction cartridges (HLB and ProElut PXC). Quantification of the four β2-agonists was achieved by HPLC-MS/MS in multiple reaction monitoring (MRM) using internal standard method. The limits of detection (S/N=3) of clenbuterol, salbutamol, ractopamine and terbutaline were 0...
February 2016: Se Pu, Chinese Journal of Chromatography
Guanglei Li, Yuhua Fu, Xiaosong Han, Xinyun Li, Changchun Li
Clenbuterol is a β-adrenergic agonist used as additive to increase the muscle mass of meat-producing animals. Previous studies were limited to evaluations of animal growth performance and determination of the residues. Several studies have focused on urine samples. Little information about the underlying molecular mechanisms that can explain Clenbuterol metabolism and promote energy repartition in animal muscle and fatty tissue is available. Therefore, this research aims to detect the metabolite variations in muscle and fatty tissue acquired from Chinese pigs fed with Clenbuterol using gas chromatography/mass spectrometry (GC/MS)...
July 22, 2016: Journal of Chromatography. A
Rahul S Pawar, Erich Grundel
The multi-billion dollar dietary supplement industry is global in reach. The industry has been criticized for problems related to poor quality control, safety, misbranding, and adulteration. In this review, we describe how the US Food and Drug Administration (FDA) regulates dietary supplements within the framework of the Federal Food, Drug, and Cosmetic Act (FD&C Act). The Dietary Supplement Health and Education Act of 1994 (DSHEA), which amended the FD&C Act, gave the FDA the authority to promulgate Good Manufacturing Practices for dietary supplements and required that manufacturers provide the FDA information supporting a conclusion that the ingredients are reasonably expected to be safe if the dietary ingredients were not marketed in the USA before 15 October 1994...
June 3, 2016: Drug Testing and Analysis
Sovichea Lay, Hai-Ning Yu, Bao-Xiang Hu, Sheng-Rong Shen
A pre-treatment methodology for clenbuterol hydrochloride (CLEN) isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers (MIPs). CLEN-imprinted polymers were synthesized by the combined use of ally-β-cyclodextrin (ally-β-CD) and methacrylic acid (MAA), allyl-β-CD and acrylonitrile (AN), and allyl-β-CD and methyl methacrylate (MMA) as the binary functional monomers. MAA-linked allyl-β-CD MIPs (M-MAA) were characterized by Fourier transform-infrared (FT-IR) spectroscopy and a scanning electron microscope (SEM)...
June 2016: Journal of Zhejiang University. Science. B
Shuaijuan Han, Tianjiao Zhou, Bingjie Yin, Pingli He
The objective of this research was to develop a multiplex dipstick immunoassay method for the simultaneous determination of multi-veterinary drug residues, such as β-agonists, sulfonamides, and tetracyclines in milk, urine, and serum. The multiplex dipstick assay format was based on an indirect competitive approach: Three test lines (different antigens) and one control line (goat anti-mouse IgG) were located on the strip membrane. Labeled antibodies were freeze-dried in microwells. Samples did not require pretreatment and could be directly analyzed within 10 min...
July 13, 2016: Analytica Chimica Acta
Yoshiki Ohnuki, Daisuke Umeki, Yasumasa Mototani, Kouichi Shiozawa, Megumi Nariyama, Aiko Ito, Naoya Kawamura, Yuka Yagisawa, Huiling Jin, Wenqian Cai, Kenji Suita, Yasutake Saeki, Takayuki Fujita, Yoshihiro Ishikawa, Satoshi Okumura
Clenbuterol (CB), a selective β2-adrenergic receptor (AR) agonist, induces muscle hypertrophy and counteracts muscle atrophy. However, it is paradoxically less effective in slow-twitch muscle than in fast-twitch muscle, though slow-twitch muscle has a greater density of β-AR We recently demonstrated that Epac1 (exchange protein activated by cyclic AMP [cAMP]1) plays a pivotal role in β2-AR-mediated masseter muscle hypertrophy through activation of the Akt and calmodulin kinase II (CaMKII)/histone deacetylase 4 (HDAC4) signaling pathways...
May 2016: Physiological Reports
Yayun Yang, Huan Zhang, Chusen Huang, Dapeng Yang, Nengqing Jia
Clenbuterol (CLB), a kind of β2-adrenergic agonists, could disrupt cardiovascular and central nervous system. In this work, a new electrochemical non-enzyme sensor for detecting Clenbuterol (CLB) was fabricated based on MoS2-Au-PEI-hemin layered nanocomposites. The two-dimensional (2-D) MoS2 nanosheets were first in-situ assembled with Au nanoparticles, and polyethylenimine (PEI), then hemin molecules were immobilized onto the MoS2-Au-PEI film-modified glassy carbon electrode (GCE) via amide bond. Scanning electron microscopy (SEM) and Zeta potential measurements were employed to characterize the MoS2-based nanomaterials...
April 7, 2016: Biosensors & Bioelectronics
Yufei Zhu, Shuyu Xie, Dongmei Chen, Yuanhu Pan, Wei Qu, Xu Wang, Zhenli Liu, Dapeng Peng, Lingli Huang, Yanfei Tao, Zonghui Yuan
A comprehensive strategy combining a quantitative method was developed for 30 banned drugs including β-agonists, hormones, glucocorticoid and psychiatric drugs in swine and chicken feeds. This rapid, simple and effective extraction method was based on matrix solid-phase dispersion and electrospray ionization tandem mass spectrometry. The quantitative method was validated after previous statistical optimization of the main parameters of matrix solid-phase dispersion. The limit of quantification of dopamine hydrochloride, chlormadinone acetate, melengestrol acetate, testosterone propionate, nandrolone and midazolam was 2 μg/kg and that of the other 24 drugs was 1 μg/kg...
July 2016: Journal of Separation Science
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