AIM:To investigate the metabolic changes in skeletal muscle and/or adipose tissue in glucagon-like peptide-1-induced improvement of nonalcoholic fatty liver disease(NAFLD).METHODS:Male Wistar rats were fed either a co...AIM:To investigate the metabolic changes in skeletal muscle and/or adipose tissue in glucagon-like peptide-1-induced improvement of nonalcoholic fatty liver disease(NAFLD).METHODS:Male Wistar rats were fed either a control diet(control group)or a high-fat diet(HFD).After 4wk,the HFD-fed rats were subdivided into two groups;one group was injected with exenatide[HFD-Ex(+)group]and the other with saline[HFD-Ex(-)group]every day for 12 wk.The control group received saline and were fed a control diet.Changes in weight gain,energy intake,and oxygen consumption were analyzed.Glucose tolerance tests were performed after 8 wk of treatment.Histological assessments were performed in liver and adipose tissue.RNA expression levels of lipid metabolism related genes were evaluated in liver,skeletal muscle,and adipose tissue.RESULTS:Exenatide attenuated weight gain[HFDEx(-)vs HFD-Ex(+)]and reduced energy intake,which was accompanied by an increase in oxygen consumption and a decrease in the respiratory exchange ratio[HFD-Ex(-)vs HFD-Ex(+)].However,exenatide did not affect glucose tolerance.Exenatide reduced lipid content in the liver and adipose tissue.Exenatide did not affect the expression of lipid metabolism-related genes in the liver or skeletal muscle.In adipose tissue,exenatide significantly upregulated lipolytic genes,including hormone-sensitive lipase,carnitine palmitoyltransferase-1,long-chain acyl-CoA dehydrogenase,and acyl-CoA oxidase 1[HFD-Ex(-)vs HFD-Ex(+)].Exenatide also upregulated catalase and superoxide dismutase 2[HFD-Ex(-)vs HFD-Ex(+)].CONCLUSION:In addition to reducing appetite,enhanced lipid use by exenatide in adipose tissue may reduce hepatic lipid content in NAFLD,most likely by decreasing lipid influx into the liver.展开更多
A highly sensitive ultra-high-performance liquid chromatographic-tandem mass spectro- metry （UPLC/MS/MS） method was developed for the quantification of the synthetic peptide drug of exenatide in monkey plasma. Sampl...A highly sensitive ultra-high-performance liquid chromatographic-tandem mass spectro- metry （UPLC/MS/MS） method was developed for the quantification of the synthetic peptide drug of exenatide in monkey plasma. Sample preparation was carried out by solid-phase extraction （SPE）, and bivalirudin was used as the internal standard （IS）. An excellent chromatographic separation was obtained on a reversed-phase C1s column with a gradient elution. Detection utilized a Qtrap 5500 system operated in the positive ion mode with multiple reaction monitoring （MRM）. The proposed method was validated by assessing the specificity, linearity, intra- and inter-day precision and accuracy, recovery, and stability. The method resulted in a linear calibration range of 0.10-30 ng/mL, extracting with only 50 μL monkey plasma aliquots. The intra- and inter-day precisions （as relative standard deviation） were less than 7.5% and 9.6%, respectively. The methodcould be successfully utilized for the pharrnacokinetic study of exenatide in monkeys following a single subcutaneous injection of Byetta.展开更多
The development of biotechnology-based active pharmaceutical ingredients, such as GLP-1 analogs, brought changes in type 2 diabetes treatment options. For better therapeutic efficiency, these active pharmaceutical ing...The development of biotechnology-based active pharmaceutical ingredients, such as GLP-1 analogs, brought changes in type 2 diabetes treatment options. For better therapeutic efficiency, these active pharmaceutical ingredients require appropriate administration, without the development of adverse effects or toxicity. Therefore, it is required to develop several quantification methods for GLP-1 analogs products, in order to achieve the therapeutic goals, among which ELISA and HPLC arise. These methods are developed, optimized and validated in order to determine GLP-1 analogs, not only in final formulation of the active pharmaceutical ingredient, but also during preclinical and clinical trials assessment. This review highlights the role of ELISA and HPLC methods that have been used during the assessment for GLP-1 analogs, especially for exenatide.展开更多
Exenatide（synthetic exendin-4）, which has been approved by the Food and Drug Administration（FDA） for the adjunctive treatment of patients with type 2 diabetes, is an incretin mimetic agent. The development and val...Exenatide（synthetic exendin-4）, which has been approved by the Food and Drug Administration（FDA） for the adjunctive treatment of patients with type 2 diabetes, is an incretin mimetic agent. The development and validation of a RP-HPLC method for the quantification of the exenatide in poly（lactic-co-glycolic acid）（PLGA） microspheres is described. Separation was performed on a C4 column via a mobile phase consisting of ACN：KH2PO4（0.02 tool/L, pH=2.5） gradient elution from 30：70 to 45：55（volume ratio） in 30 min. Multi-diode array detection（DAD） appears to be most appropriate to evaluate the spectral purity of exenatide. The limits of detection and quantification of exenatide were 0.4 and 1.2 μg/mL, respectively. The calibration curve of exenatide was linear in a range of 0.025--0.2 mg/mL with a correlation coefficient of 0.9995. The results of validation study show that this method is specific, accurate（recovery〉95%）, precise（RSD〈2.0%） and robust.展开更多
文摘AIM:To investigate the metabolic changes in skeletal muscle and/or adipose tissue in glucagon-like peptide-1-induced improvement of nonalcoholic fatty liver disease(NAFLD).METHODS:Male Wistar rats were fed either a control diet(control group)or a high-fat diet(HFD).After 4wk,the HFD-fed rats were subdivided into two groups;one group was injected with exenatide[HFD-Ex(+)group]and the other with saline[HFD-Ex(-)group]every day for 12 wk.The control group received saline and were fed a control diet.Changes in weight gain,energy intake,and oxygen consumption were analyzed.Glucose tolerance tests were performed after 8 wk of treatment.Histological assessments were performed in liver and adipose tissue.RNA expression levels of lipid metabolism related genes were evaluated in liver,skeletal muscle,and adipose tissue.RESULTS:Exenatide attenuated weight gain[HFDEx(-)vs HFD-Ex(+)]and reduced energy intake,which was accompanied by an increase in oxygen consumption and a decrease in the respiratory exchange ratio[HFD-Ex(-)vs HFD-Ex(+)].However,exenatide did not affect glucose tolerance.Exenatide reduced lipid content in the liver and adipose tissue.Exenatide did not affect the expression of lipid metabolism-related genes in the liver or skeletal muscle.In adipose tissue,exenatide significantly upregulated lipolytic genes,including hormone-sensitive lipase,carnitine palmitoyltransferase-1,long-chain acyl-CoA dehydrogenase,and acyl-CoA oxidase 1[HFD-Ex(-)vs HFD-Ex(+)].Exenatide also upregulated catalase and superoxide dismutase 2[HFD-Ex(-)vs HFD-Ex(+)].CONCLUSION:In addition to reducing appetite,enhanced lipid use by exenatide in adipose tissue may reduce hepatic lipid content in NAFLD,most likely by decreasing lipid influx into the liver.
基金supported by the National Basic Research Program of China (973 Program) (No. 2010CB735602 and No. 2012CB724003)
文摘A highly sensitive ultra-high-performance liquid chromatographic-tandem mass spectro- metry （UPLC/MS/MS） method was developed for the quantification of the synthetic peptide drug of exenatide in monkey plasma. Sample preparation was carried out by solid-phase extraction （SPE）, and bivalirudin was used as the internal standard （IS）. An excellent chromatographic separation was obtained on a reversed-phase C1s column with a gradient elution. Detection utilized a Qtrap 5500 system operated in the positive ion mode with multiple reaction monitoring （MRM）. The proposed method was validated by assessing the specificity, linearity, intra- and inter-day precision and accuracy, recovery, and stability. The method resulted in a linear calibration range of 0.10-30 ng/mL, extracting with only 50 μL monkey plasma aliquots. The intra- and inter-day precisions （as relative standard deviation） were less than 7.5% and 9.6%, respectively. The methodcould be successfully utilized for the pharrnacokinetic study of exenatide in monkeys following a single subcutaneous injection of Byetta.
文摘The development of biotechnology-based active pharmaceutical ingredients, such as GLP-1 analogs, brought changes in type 2 diabetes treatment options. For better therapeutic efficiency, these active pharmaceutical ingredients require appropriate administration, without the development of adverse effects or toxicity. Therefore, it is required to develop several quantification methods for GLP-1 analogs products, in order to achieve the therapeutic goals, among which ELISA and HPLC arise. These methods are developed, optimized and validated in order to determine GLP-1 analogs, not only in final formulation of the active pharmaceutical ingredient, but also during preclinical and clinical trials assessment. This review highlights the role of ELISA and HPLC methods that have been used during the assessment for GLP-1 analogs, especially for exenatide.
基金Supported by the Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period,China(No.2008ZX10001-012)
文摘Exenatide（synthetic exendin-4）, which has been approved by the Food and Drug Administration（FDA） for the adjunctive treatment of patients with type 2 diabetes, is an incretin mimetic agent. The development and validation of a RP-HPLC method for the quantification of the exenatide in poly（lactic-co-glycolic acid）（PLGA） microspheres is described. Separation was performed on a C4 column via a mobile phase consisting of ACN：KH2PO4（0.02 tool/L, pH=2.5） gradient elution from 30：70 to 45：55（volume ratio） in 30 min. Multi-diode array detection（DAD） appears to be most appropriate to evaluate the spectral purity of exenatide. The limits of detection and quantification of exenatide were 0.4 and 1.2 μg/mL, respectively. The calibration curve of exenatide was linear in a range of 0.025--0.2 mg/mL with a correlation coefficient of 0.9995. The results of validation study show that this method is specific, accurate（recovery〉95%）, precise（RSD〈2.0%） and robust.
