Objective To investigate effects of clenbuterol （CLB） on testicular ultrastructure of rat. Methods Twenty adult male Sprague-Dawley rats were randomly divided into four groups （5 rats per group）. CLB solved in nor...Objective To investigate effects of clenbuterol （CLB） on testicular ultrastructure of rat. Methods Twenty adult male Sprague-Dawley rats were randomly divided into four groups （5 rats per group）. CLB solved in normal saline solution was given at the dose of O mg/kg body weight （bw） （group A, as control）, 0.4 mg/kg bw （group B）, 2.0 mg/kg bw （group C）, and 18.5 mg/kg bw （group D）for 14 d by garage consecutively, respectively. Transmission electron microscopy was used to observe changes on testicular ultrastructure. Results In group B, some small vacuoles were found in Sertoli cells. In groups C and D, vacuoles were common in Sertoli cells and spermatogonia. The phenomenon of vacuolation in group D was more severe than that in group C. In group D, basal membrane showed some irregular and wrinkled changes, Leydig cells had more vacuoles and increased lipid droplets. Conclusion Testicular ultrastructure of rat had pathological changes after CLB exposure, and the alterations became more severe with the increasing doses.展开更多
To make more homogenous organic monolithic structure, reversible addition-fragmentation chain transfer （RAFT） process was employed in the synthesis of the clenbuterol imprinted polymer. In the synthesis, the influen...To make more homogenous organic monolithic structure, reversible addition-fragmentation chain transfer （RAFT） process was employed in the synthesis of the clenbuterol imprinted polymer. In the synthesis, the influence of synthetic conditions on the polymer structure and separation efficiency was studied. The result demonstrated that the imprinted columns prepared with RAFT process have higher column efficiency and selectivity than the columns prepared with conventional polymerization in the present study, which may result from the higher surface area, smaller pore size and the narrower globule size distribution in their structures. The result indicated that RAFT polymerization provided better conditions for the clenbuterol imprinted monolithic polymer preparation. 2009 Xiang Chao Dong. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
To investigate the effect of clenbuterol hydrochloride on the in vitro development of both 1 cell and 2 cell mouse embryos. Methods The cultural systems of both 1 cell and 2 cell mouse embryo were used to dete...To investigate the effect of clenbuterol hydrochloride on the in vitro development of both 1 cell and 2 cell mouse embryos. Methods The cultural systems of both 1 cell and 2 cell mouse embryo were used to determine the effect of clenbuterol hydrochloride at doses of 1 ng/mL, 3 ng/mL, and 10 ng/mL on developmental rates of mouse embryos. Results When 1 cell embryos cultured with 1 ng/mL of clenbuterol hydrochloride, developmental rates from the 4 cell stage to blastocyst stage were significantly lower than those in the control group (P<0.05), but on dosages of 3 ng/mL and 10 ng/mL, the inhibiting effects on embryo development were significantly increased (P<0.01). When 2 cell embryos cultured with 1 ng/mL of clenbuterol hydrochloride, obvious differences in developmental rates were not found between the 2 cell embryo group and the control (P>0.05). However, at levels of 3 ng/mL and 10 ng/mL, significant decrease of developmental rates in 2 cell embryos was observed from the 4 cell and from the 8 cell stage, respectively (P<0.05). Embryos cultured with clenbuterol hydrochloride appeared to have more granules, fragments and degeneration than those in the control. Conclusion Clenbuterol hydrochloride has a toxic effect on the mouse embryos, and the effect is in a dose dependent. 1 cell mouse embryos cultured with clenbuterol hydrochloride could be easily inhibited at 2 cell stage, but the effect of clenbuterol hydrochloride on development of the late 2 cell embryos would be reduced.展开更多
Both clenbuterol(CLB)and ractopamine(RAC)areβ-adrenergic agonists.After long-term excessive intake,there will be adverse reactions such as headache,chest tightness,limb numbness,and serious lifethreatening.Simultaneo...Both clenbuterol(CLB)and ractopamine(RAC)areβ-adrenergic agonists.After long-term excessive intake,there will be adverse reactions such as headache,chest tightness,limb numbness,and serious lifethreatening.Simultaneous detection of CLB and RAC in related samples is of great importance for human health.In this work,we outline a microfluidics-based indirect competitive immunoassay(MICI)system that can sensitively detect residual CLB and RAC in pork,swine blood and swine urine.The rapid detection of multiple samples can be achieved in one chip,which greatly improves the detection efficiency.This method has good stability and reproducibility and the microfluidic chips are easy to manufacture.The linear ranges for CLB and RAC detection by MICI are 0.1-2.5 ng/mL and 0.1-5 ng/mL,and the limits of detection(LODs)are 0.094 ng/mL and 0.091 ng/mL,respectively.This straightforward and portable immunoassay system provides a good platform for rapid detection of harmful substances in food samples.展开更多
Pig （Sus scrofa） fat accumulation can be reduced by feeding with high dosages of clenbuterol, but the molecular mechanism has not yet been explained. In our study, a porcine cDNA microarray representing 3 358 pig ge...Pig （Sus scrofa） fat accumulation can be reduced by feeding with high dosages of clenbuterol, but the molecular mechanism has not yet been explained. In our study, a porcine cDNA microarray representing 3 358 pig genes was successfully developed. This microarray is the first porcine DNA microarray in China and its false positive rate is 0.98%, which means the microarray platform is reliable. The microarray can be used to study gene expression profiles in multiple pig tissues because the present genes percentage of adipose, skeletal muscle, heart, liver, lung, kidney, and spleen were all more than 60%. This microarray was used to identify the genes responding to clenbuterol stimulation in pig internal organs, including heart, liver, lung, spleen, and kidney. Many genes were identified including enzymes involved in lipids metabolism （lipoprotein lipase up-regulated in liver, heart and lung, ATP-citrate lyase and carnitine palmitoyltransferase II precursor up-regulated in liver, succinyl-CoA up-regulated in lung, mitochondrial malate dehydrogenase down-regulated in spleen）, and signaling pathway genes （cAMP-protein kinase A signaling pathway was found up-regulated in liver, heart, lung, and kidney as reported previously, while transforming growth factor was found down-regulated in heart and lung）. However, no common gene responding to clenbuterol administration was found in all tissues. The expression levels of 14 genes were analyzed using real-time PCR with 82.1% of them induced to express similar magnitudes as in the microarray analyses. This work offers some understanding of how clenbuterol so effectively reduces pig adipose accumulation on the molecular level.展开更多
Objective To investigate effects of clenbuterol （CLB） on the peroxisome proliferators- activated receptor γ （PPARγ） expression in adipose tissues of rats. Methods Twenty adult female Sprague-Dawley rats were ran...Objective To investigate effects of clenbuterol （CLB） on the peroxisome proliferators- activated receptor γ （PPARγ） expression in adipose tissues of rats. Methods Twenty adult female Sprague-Dawley rats were randomly divided into 4 groups （5 rats per group）. CLB solved in normal saline solution was given at the dose of 0 mg/kg body weight （bw） （group A, as the control）, 0.4 mg/kg bw （group B, low-dose group）, 2.0 mg/kg bw （group C, mid-dose group）, and 18.5 mg/kg bw （group D, high-dose group）for 14 d by gavage consecutively, respectively. Methods of immunohistochemistry, quantitative Real-time PCR and Western blotting were performed to detect expression of PPARγ in the adipose tissue samples. Results PPARγ-positive immunostaining was strong in the controls and weak in the experimental groups. There was no difference on PPARγmRNA and protein between the low-dose group and the control （P〉0.05）. With the increase of CLB doses, expression levels of PPARγmRNA and protein were significantly lower in mid- or high-dose group than those in the control （19〈0.01）. Conclusions The PPARγ expression in adipose tissues of rats could be down-regulated after CLB exposure, and the decrease became more severe with the increasing doses.展开更多
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 pol-...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 pol- ymers were synthesized by the combined use of ally-β-cyclodextrin （ally-13-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）. Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references： AN-linked allyl-β-CD MIPs （M-AN） and MMA-linked allyl-β-CD MIPs （M-MMA）. M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction （MISPE） micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation （RSD） ≤4.45%.展开更多
A novel immunosensor for determination of clenbuterol was described in this paper. Horseradish peroxidase (HRP) and Monoclonal antibody against clenbuterol was covalently immobilized onto the cellulose acetate membran...A novel immunosensor for determination of clenbuterol was described in this paper. Horseradish peroxidase (HRP) and Monoclonal antibody against clenbuterol was covalently immobilized onto the cellulose acetate membrane which was used as one-touch immunochips. After 20 min of competitive reaction of clenbuterol in samples against glucose oxidase-conjugated clenbuterol (CLB-GOD) with anti-clenbuteol antibody immobilized on the membrane, the one-touch transducer was fixed on the Nafion - ferrocene modified glass-carbon electrode (GCE, working electrode) by “O” ring. The increased current changes (ΔI) were recorded for the quantitative determination of clenbuterol by derivative cyclic voltammetry. Experimental results showed that a very effective system for electron transmission had been established using dual-enzyme system and Nafion-ferrocene modified GCE. Quantitative analysis of clenbuterol could be easily performed on this kind of immunosensor, which showed the advantage of time-saving and high sensitivity (The detecting limit of this kind of immunosensor can be down to 100 ng/L). In addition, other conditions affecting the electrochemical response were also discussed in detail.展开更多
Four-factor and three-level orthogonal experimental design(L9(34))was used in the experiment.The effects of three genotypes:Germany SAB three-bred-cross rabbits(S2),New Zealand purebred(N),and crossbred rabbits(ON);th...Four-factor and three-level orthogonal experimental design(L9(34))was used in the experiment.The effects of three genotypes:Germany SAB three-bred-cross rabbits(S2),New Zealand purebred(N),and crossbred rabbits(ON);three levels of Clenbuterol treatment: 1 ng.g-1,2 ng.g-1and 3 ng.g-1,and three feeding methods:5-day,7-day and 10-day withdrawal period after two weeks of feeding Clenbuterol(CL)on bodyweight gain were evaluated.CL apparently improved average daily gain(ADG)of rabbits.70-day ADG of 5-day and 10-day withdrawal were higher than that of 7-day withdrawal,70-day ADG of S2 genotype was significantly higher than that of the control and N genotype was significant.Genotype,additive dose and feeding method had significant effects on overall-stage ADG.ON genotype,2 ng.g-1 dose and 5-day withdrawal feeding method was the best.Responses of different genotype to Clenbuterol appeared different at experimental prophase or whole experimental period.展开更多
Objective adiponectin Methods To investigate the effects of clenbuterol （CLB） on the expression of （ADP） in adipocytes. 3T3-L1 pre-adipocytes were induced into mature adipocytes, and then randomly divided into fo...Objective adiponectin Methods To investigate the effects of clenbuterol （CLB） on the expression of （ADP） in adipocytes. 3T3-L1 pre-adipocytes were induced into mature adipocytes, and then randomly divided into four groups based on doses of CLB： 0 12mol/L （group A, as the control）, 0.5 12mol/L （group B, low-dose group）, 5 μmol/L （group C, mid-dose group）, and 50 μmol/L （group D, high-dose group）, respectively. These four groups were cultured for both 12 h and 24 h. After CLB exposure, the effects of CLB on the expression of ADP in adipocytes were detected by qPCR and Western blotting analysis, and cell viability was quantified by the methyl thiazolyl tetrazolium assay. Results At 12 h, there was no difference in the expression of ADP between group A and group B or C （P〉0.05）. With the increase of CLB doses, the expression level of ADP in group D was lower than that in group A （P〈0.01）. After 24 h of incubation, compared with group A, there was a greater decrease in the expression of ADP in group B （P〈0.05）, and this suppression was more remarkable in group C or D （P〈O.O1）. At 12 h, viability of the cells in group B had no difference compared with group A （P〉 0.05）. A significant decrease of cell viability was counted in group C or D （P〈0.05）. At 24 h, with the increasing doses of CLB, viability of the cells showed more severe decrease in three experimental groups compared with the control （P〈0.01）. Conclusion After CLB exposure, the expression of ADP could be down-regulated and the decrease was more severe with the increasing doses of CLB.展开更多
The direct detection of clenbuterol（CL） in pig liver without any extraction separation at a pyrrole-DNA modified boron-doped diamond（BDD） electrode is reported. The pyrrole-DNA modified BDD electrode has a strong ...The direct detection of clenbuterol（CL） in pig liver without any extraction separation at a pyrrole-DNA modified boron-doped diamond（BDD） electrode is reported. The pyrrole-DNA modified BDD electrode has a strong electrocatalytic effect on the redox reaction of CL. One oxidization and two reduction peaks of CL appear at 340. 2, 299. 8 and 166. 6 mV（ versus SCE）, respectively. The pyrrole polymer alone cannot electrocatalyze the above reaction at a BDD electrode ; the electrocatalytic effect of a BDD electrode modified with DNA membrane is unsufficient for the analytical detection of CL; the replacement of boron-doped diamond by glass carbon makes the electrocatalytic reaction impossible ; the redox process is pH dependent. The influences of various experimental parameters on the pyrrole-DNA modified BDD electrode were investigated. A sensitive cyclic vohammetric response for CL was obtained in a linear range from 3.4 × 10^-6 to 5 × 10^ -4 mol/L with a detection limit of 8.5 × 10^-7 mol/L. A mean recovery of 102. 7% of CL in the pig liver sample solution and a reproducibility of 3.2% were obtained.展开更多
文摘目的研究Clenbuterol对于促进脊髓半横切(SCI)后轴突再生和运动功能恢复的功效。方法成年Wistar大鼠(n=10-12)接受硬脊膜内的第7颈段脊髓单侧半横切显微手术。Clenbuterol以9 mg/L的剂量加入饮用水中,而对照组未给予任何治疗。采用Cylinder试验和患肢抓力试验观察运动功能的恢复状况。行为学观察期(6周)结束后,大鼠接受第二胸段脊髓处椎板切开术,4%Fluorogold微量注射进入红核脊髓束,一周后被处死。结果运动功能逐渐恢复,从SCI后第3周开始,Clenbuterol治疗组显著优于对照组(最终患肢抓力:403.45±19.82g vs 335.13±13.48g,p<0.05);在Cylinder试验中,双侧前肢共同使用触壁的百分比,Clenbuterol组显著高于对照组(43.39%±5.85%vs 19.42%±6.61%,p<0.05)。Clenbuterol治疗显著地降低了SCI后继发性组织损伤,提高了pCREB阳性细胞核在整个SCI点的表达水平。与对照组相比,Clenbuterol显著地促进了红核脊髓束轴突的再生。结论脊髓损伤后,Clenbuterol可促进离断的轴突再生以及运动功能的恢复。
基金supported by Science and Technology Planning Project of Guangzhou City,China(No.2013 00000114)
文摘Objective To investigate effects of clenbuterol （CLB） on testicular ultrastructure of rat. Methods Twenty adult male Sprague-Dawley rats were randomly divided into four groups （5 rats per group）. CLB solved in normal saline solution was given at the dose of O mg/kg body weight （bw） （group A, as control）, 0.4 mg/kg bw （group B）, 2.0 mg/kg bw （group C）, and 18.5 mg/kg bw （group D）for 14 d by garage consecutively, respectively. Transmission electron microscopy was used to observe changes on testicular ultrastructure. Results In group B, some small vacuoles were found in Sertoli cells. In groups C and D, vacuoles were common in Sertoli cells and spermatogonia. The phenomenon of vacuolation in group D was more severe than that in group C. In group D, basal membrane showed some irregular and wrinkled changes, Leydig cells had more vacuoles and increased lipid droplets. Conclusion Testicular ultrastructure of rat had pathological changes after CLB exposure, and the alterations became more severe with the increasing doses.
基金supported by the National Natural Science Foundation of China(No.20575030)
文摘To make more homogenous organic monolithic structure, reversible addition-fragmentation chain transfer （RAFT） process was employed in the synthesis of the clenbuterol imprinted polymer. In the synthesis, the influence of synthetic conditions on the polymer structure and separation efficiency was studied. The result demonstrated that the imprinted columns prepared with RAFT process have higher column efficiency and selectivity than the columns prepared with conventional polymerization in the present study, which may result from the higher surface area, smaller pore size and the narrower globule size distribution in their structures. The result indicated that RAFT polymerization provided better conditions for the clenbuterol imprinted monolithic polymer preparation. 2009 Xiang Chao Dong. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金the Natural Science Foundation of Guangdong ProvinceChina
文摘To investigate the effect of clenbuterol hydrochloride on the in vitro development of both 1 cell and 2 cell mouse embryos. Methods The cultural systems of both 1 cell and 2 cell mouse embryo were used to determine the effect of clenbuterol hydrochloride at doses of 1 ng/mL, 3 ng/mL, and 10 ng/mL on developmental rates of mouse embryos. Results When 1 cell embryos cultured with 1 ng/mL of clenbuterol hydrochloride, developmental rates from the 4 cell stage to blastocyst stage were significantly lower than those in the control group (P<0.05), but on dosages of 3 ng/mL and 10 ng/mL, the inhibiting effects on embryo development were significantly increased (P<0.01). When 2 cell embryos cultured with 1 ng/mL of clenbuterol hydrochloride, obvious differences in developmental rates were not found between the 2 cell embryo group and the control (P>0.05). However, at levels of 3 ng/mL and 10 ng/mL, significant decrease of developmental rates in 2 cell embryos was observed from the 4 cell and from the 8 cell stage, respectively (P<0.05). Embryos cultured with clenbuterol hydrochloride appeared to have more granules, fragments and degeneration than those in the control. Conclusion Clenbuterol hydrochloride has a toxic effect on the mouse embryos, and the effect is in a dose dependent. 1 cell mouse embryos cultured with clenbuterol hydrochloride could be easily inhibited at 2 cell stage, but the effect of clenbuterol hydrochloride on development of the late 2 cell embryos would be reduced.
基金the National Key R&D Program of China(Nos.2018YFA0902600,2017YFA0205901)the National Natural Science Foundation of China(Nos.21535001,81730051,21761142006)the Chinese Academy of Sciences(Nos.QYZDJ-SSW-SLH039,121D11KYSB20170026,XDA16020902)for financial support。
文摘Both clenbuterol(CLB)and ractopamine(RAC)areβ-adrenergic agonists.After long-term excessive intake,there will be adverse reactions such as headache,chest tightness,limb numbness,and serious lifethreatening.Simultaneous detection of CLB and RAC in related samples is of great importance for human health.In this work,we outline a microfluidics-based indirect competitive immunoassay(MICI)system that can sensitively detect residual CLB and RAC in pork,swine blood and swine urine.The rapid detection of multiple samples can be achieved in one chip,which greatly improves the detection efficiency.This method has good stability and reproducibility and the microfluidic chips are easy to manufacture.The linear ranges for CLB and RAC detection by MICI are 0.1-2.5 ng/mL and 0.1-5 ng/mL,and the limits of detection(LODs)are 0.094 ng/mL and 0.091 ng/mL,respectively.This straightforward and portable immunoassay system provides a good platform for rapid detection of harmful substances in food samples.
基金supported by the National Natural Science Foundation of China (30800778 and 31072004)the Hebei Natural Science Foundation (C2009000871)+2 种基金the Hebei Educational Foundation,China (2009119)the Hebei Excellent Expert for Overseas Advanced Training Program (2009)Scientific Research Innovation Team Funds of Hebei Normal University of Sci & Tech,China
文摘Pig （Sus scrofa） fat accumulation can be reduced by feeding with high dosages of clenbuterol, but the molecular mechanism has not yet been explained. In our study, a porcine cDNA microarray representing 3 358 pig genes was successfully developed. This microarray is the first porcine DNA microarray in China and its false positive rate is 0.98%, which means the microarray platform is reliable. The microarray can be used to study gene expression profiles in multiple pig tissues because the present genes percentage of adipose, skeletal muscle, heart, liver, lung, kidney, and spleen were all more than 60%. This microarray was used to identify the genes responding to clenbuterol stimulation in pig internal organs, including heart, liver, lung, spleen, and kidney. Many genes were identified including enzymes involved in lipids metabolism （lipoprotein lipase up-regulated in liver, heart and lung, ATP-citrate lyase and carnitine palmitoyltransferase II precursor up-regulated in liver, succinyl-CoA up-regulated in lung, mitochondrial malate dehydrogenase down-regulated in spleen）, and signaling pathway genes （cAMP-protein kinase A signaling pathway was found up-regulated in liver, heart, lung, and kidney as reported previously, while transforming growth factor was found down-regulated in heart and lung）. However, no common gene responding to clenbuterol administration was found in all tissues. The expression levels of 14 genes were analyzed using real-time PCR with 82.1% of them induced to express similar magnitudes as in the microarray analyses. This work offers some understanding of how clenbuterol so effectively reduces pig adipose accumulation on the molecular level.
基金supported by Science and Technology Planning Project of Guangzhou City,China(No.201300000114)
文摘Objective To investigate effects of clenbuterol （CLB） on the peroxisome proliferators- activated receptor γ （PPARγ） expression in adipose tissues of rats. Methods Twenty adult female Sprague-Dawley rats were randomly divided into 4 groups （5 rats per group）. CLB solved in normal saline solution was given at the dose of 0 mg/kg body weight （bw） （group A, as the control）, 0.4 mg/kg bw （group B, low-dose group）, 2.0 mg/kg bw （group C, mid-dose group）, and 18.5 mg/kg bw （group D, high-dose group）for 14 d by gavage consecutively, respectively. Methods of immunohistochemistry, quantitative Real-time PCR and Western blotting were performed to detect expression of PPARγ in the adipose tissue samples. Results PPARγ-positive immunostaining was strong in the controls and weak in the experimental groups. There was no difference on PPARγmRNA and protein between the low-dose group and the control （P〉0.05）. With the increase of CLB doses, expression levels of PPARγmRNA and protein were significantly lower in mid- or high-dose group than those in the control （19〈0.01）. Conclusions The PPARγ expression in adipose tissues of rats could be down-regulated after CLB exposure, and the decrease became more severe with the increasing doses.
基金Project supported by the Department of Science and Technology of Zhejiang Province(No.2013C02022-2/01),China
文摘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 pol- ymers were synthesized by the combined use of ally-β-cyclodextrin （ally-13-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）. Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references： AN-linked allyl-β-CD MIPs （M-AN） and MMA-linked allyl-β-CD MIPs （M-MMA）. M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction （MISPE） micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation （RSD） ≤4.45%.
文摘A novel immunosensor for determination of clenbuterol was described in this paper. Horseradish peroxidase (HRP) and Monoclonal antibody against clenbuterol was covalently immobilized onto the cellulose acetate membrane which was used as one-touch immunochips. After 20 min of competitive reaction of clenbuterol in samples against glucose oxidase-conjugated clenbuterol (CLB-GOD) with anti-clenbuteol antibody immobilized on the membrane, the one-touch transducer was fixed on the Nafion - ferrocene modified glass-carbon electrode (GCE, working electrode) by “O” ring. The increased current changes (ΔI) were recorded for the quantitative determination of clenbuterol by derivative cyclic voltammetry. Experimental results showed that a very effective system for electron transmission had been established using dual-enzyme system and Nafion-ferrocene modified GCE. Quantitative analysis of clenbuterol could be easily performed on this kind of immunosensor, which showed the advantage of time-saving and high sensitivity (The detecting limit of this kind of immunosensor can be down to 100 ng/L). In addition, other conditions affecting the electrochemical response were also discussed in detail.
文摘Four-factor and three-level orthogonal experimental design(L9(34))was used in the experiment.The effects of three genotypes:Germany SAB three-bred-cross rabbits(S2),New Zealand purebred(N),and crossbred rabbits(ON);three levels of Clenbuterol treatment: 1 ng.g-1,2 ng.g-1and 3 ng.g-1,and three feeding methods:5-day,7-day and 10-day withdrawal period after two weeks of feeding Clenbuterol(CL)on bodyweight gain were evaluated.CL apparently improved average daily gain(ADG)of rabbits.70-day ADG of 5-day and 10-day withdrawal were higher than that of 7-day withdrawal,70-day ADG of S2 genotype was significantly higher than that of the control and N genotype was significant.Genotype,additive dose and feeding method had significant effects on overall-stage ADG.ON genotype,2 ng.g-1 dose and 5-day withdrawal feeding method was the best.Responses of different genotype to Clenbuterol appeared different at experimental prophase or whole experimental period.
基金supported by Science and Technology Planning Project of Guangzhou City,China(No.201300000114)
文摘Objective adiponectin Methods To investigate the effects of clenbuterol （CLB） on the expression of （ADP） in adipocytes. 3T3-L1 pre-adipocytes were induced into mature adipocytes, and then randomly divided into four groups based on doses of CLB： 0 12mol/L （group A, as the control）, 0.5 12mol/L （group B, low-dose group）, 5 μmol/L （group C, mid-dose group）, and 50 μmol/L （group D, high-dose group）, respectively. These four groups were cultured for both 12 h and 24 h. After CLB exposure, the effects of CLB on the expression of ADP in adipocytes were detected by qPCR and Western blotting analysis, and cell viability was quantified by the methyl thiazolyl tetrazolium assay. Results At 12 h, there was no difference in the expression of ADP between group A and group B or C （P〉0.05）. With the increase of CLB doses, the expression level of ADP in group D was lower than that in group A （P〈0.01）. After 24 h of incubation, compared with group A, there was a greater decrease in the expression of ADP in group B （P〈0.05）, and this suppression was more remarkable in group C or D （P〈O.O1）. At 12 h, viability of the cells in group B had no difference compared with group A （P〉 0.05）. A significant decrease of cell viability was counted in group C or D （P〈0.05）. At 24 h, with the increasing doses of CLB, viability of the cells showed more severe decrease in three experimental groups compared with the control （P〈0.01）. Conclusion After CLB exposure, the expression of ADP could be down-regulated and the decrease was more severe with the increasing doses of CLB.
基金Supported by the National Natural Science Foundation of China(Nos. 20435010, 20375012, 20205005 and 20475014).
文摘The direct detection of clenbuterol（CL） in pig liver without any extraction separation at a pyrrole-DNA modified boron-doped diamond（BDD） electrode is reported. The pyrrole-DNA modified BDD electrode has a strong electrocatalytic effect on the redox reaction of CL. One oxidization and two reduction peaks of CL appear at 340. 2, 299. 8 and 166. 6 mV（ versus SCE）, respectively. The pyrrole polymer alone cannot electrocatalyze the above reaction at a BDD electrode ; the electrocatalytic effect of a BDD electrode modified with DNA membrane is unsufficient for the analytical detection of CL; the replacement of boron-doped diamond by glass carbon makes the electrocatalytic reaction impossible ; the redox process is pH dependent. The influences of various experimental parameters on the pyrrole-DNA modified BDD electrode were investigated. A sensitive cyclic vohammetric response for CL was obtained in a linear range from 3.4 × 10^-6 to 5 × 10^ -4 mol/L with a detection limit of 8.5 × 10^-7 mol/L. A mean recovery of 102. 7% of CL in the pig liver sample solution and a reproducibility of 3.2% were obtained.
