Konjac glucomannan （KGM） was aminated by 2-chloroethyl-amine （CEA） as reagent so as to study the influence of concentration of CEA （based on the amount of KGM）, concentration of NaOH, reaction time and temperatu...Konjac glucomannan （KGM） was aminated by 2-chloroethyl-amine （CEA） as reagent so as to study the influence of concentration of CEA （based on the amount of KGM）, concentration of NaOH, reaction time and temperature on the extent of amination. And the molecular simulation technology was adopted to analyze the conformation stability of aminate （AKGM）. The results indicate that when the amount of CEA is higher, the extent of amination is higher. The optimum concentration of NaOH, reaction time and temperature are 10% NaOH, 70 ℃ and 45 rain, respectively. IR shows KGM is successfully aminated. The conformation of AKGM is in a random clew-like shape.展开更多
Background As an agonist of peroxisome proliferator-activated receptor-gamma （PPARy）, rosiglitazone can prevent acute fatty acid-induced insulin resistance in rats, however, the precise mechanisms by which rosiglita...Background As an agonist of peroxisome proliferator-activated receptor-gamma （PPARy）, rosiglitazone can prevent acute fatty acid-induced insulin resistance in rats, however, the precise mechanisms by which rosiglitazone alleviates insulin resistance induced by high-fat diet need to be further investigated.Methods Wistar rats aged 23-24 weeks were divided into three groups： （1） aged control group （OC）, （2） high-fat diet （HF） group and （3） high-fat diet plus rosiglitazone maleate tablets （HF＋Rosi） treatment group （n=20 in each group）. Insulin sensitivity was evaluated by conscious hyperinsulinemic-euglycemic clamp technique. mRNA levels of fatty acid translocase （FAT/CD36）, AMP-activated protein kinase α1 （AMPKα1）, AMPKα2 and acetyl CoA carboxylase （ACC） of rat skeletal muscle were determined using real-time PCR, while muscle camitine palmitoyltransferase-1 （CPT-1β） was determined using semi-quantitative PCR. Protein expression levels of FAT/CD36, AMPK phosphorylation （reflecting AMPK activity）, P-ACC （inversely related with ACC activity） and muscle CPT-1M in rat skeletal muscles were measured using Western blotting.Results Aged rats fed by diet rich in fat for more than 8 weeks led to significant increases of plasma lipids, skeletal muscle intramuscular triglyceride and long-chain fatty acyl-CoA （LCACoA） compared to aged rats fed by normal chow diet （OC） （P 〈0.05）, which might correlate with the lower （reduced by 42.4%） whole body insulin sensitivity in HF rats. FAT/CD36 protein concentrations and mRNA levels increased in untreated HF aged rats （P 〈0.01） and high-fat diet induced a significant decrease in P-AMPK, P-ACC, CPT-1M protein concentrations and AMPKα2 and CPT-1β mRNA levels in rat skeletal muscles （P 〈0.05）. No change in AMPKα1 mRNA levels was observed in the HF group.Conclusion High-fat diet in aged rats results in a lipid accumulation and subsequent insulin resistance, while rosiglitazone can alleviate the insulin resistance by reducing fatty acid uptake as well as enhancing lipometabolism.展开更多
基金Supported by Foundation of Minnan Normal University,the Funding(type A,No.JA11167)from the Fujian Education DepartmentNational Natural Science Foundation of China(31071518 and 31271837)+2 种基金Joint Specialized Research Fund for the Doctoral Program of Higher Education,MOE(20113515110010)Science and Technology Planning Project of technological department(2012GA7200022)Natural Science Foundation of Fujian Province(2011J01285)
文摘Konjac glucomannan （KGM） was aminated by 2-chloroethyl-amine （CEA） as reagent so as to study the influence of concentration of CEA （based on the amount of KGM）, concentration of NaOH, reaction time and temperature on the extent of amination. And the molecular simulation technology was adopted to analyze the conformation stability of aminate （AKGM）. The results indicate that when the amount of CEA is higher, the extent of amination is higher. The optimum concentration of NaOH, reaction time and temperature are 10% NaOH, 70 ℃ and 45 rain, respectively. IR shows KGM is successfully aminated. The conformation of AKGM is in a random clew-like shape.
基金This work was supported by a grant from the Hebei Provincial Natural Science Foundation of China （No. 303552）.
文摘Background As an agonist of peroxisome proliferator-activated receptor-gamma （PPARy）, rosiglitazone can prevent acute fatty acid-induced insulin resistance in rats, however, the precise mechanisms by which rosiglitazone alleviates insulin resistance induced by high-fat diet need to be further investigated.Methods Wistar rats aged 23-24 weeks were divided into three groups： （1） aged control group （OC）, （2） high-fat diet （HF） group and （3） high-fat diet plus rosiglitazone maleate tablets （HF＋Rosi） treatment group （n=20 in each group）. Insulin sensitivity was evaluated by conscious hyperinsulinemic-euglycemic clamp technique. mRNA levels of fatty acid translocase （FAT/CD36）, AMP-activated protein kinase α1 （AMPKα1）, AMPKα2 and acetyl CoA carboxylase （ACC） of rat skeletal muscle were determined using real-time PCR, while muscle camitine palmitoyltransferase-1 （CPT-1β） was determined using semi-quantitative PCR. Protein expression levels of FAT/CD36, AMPK phosphorylation （reflecting AMPK activity）, P-ACC （inversely related with ACC activity） and muscle CPT-1M in rat skeletal muscles were measured using Western blotting.Results Aged rats fed by diet rich in fat for more than 8 weeks led to significant increases of plasma lipids, skeletal muscle intramuscular triglyceride and long-chain fatty acyl-CoA （LCACoA） compared to aged rats fed by normal chow diet （OC） （P 〈0.05）, which might correlate with the lower （reduced by 42.4%） whole body insulin sensitivity in HF rats. FAT/CD36 protein concentrations and mRNA levels increased in untreated HF aged rats （P 〈0.01） and high-fat diet induced a significant decrease in P-AMPK, P-ACC, CPT-1M protein concentrations and AMPKα2 and CPT-1β mRNA levels in rat skeletal muscles （P 〈0.05）. No change in AMPKα1 mRNA levels was observed in the HF group.Conclusion High-fat diet in aged rats results in a lipid accumulation and subsequent insulin resistance, while rosiglitazone can alleviate the insulin resistance by reducing fatty acid uptake as well as enhancing lipometabolism.
