Objective: To investigate the influence of nutrients on the expression of insulin receptor and its related substrate genes in the mice muscle.Methods: C57BL/6J mice were randomly divided into 4 groups: ①HF, mice on h...Objective: To investigate the influence of nutrients on the expression of insulin receptor and its related substrate genes in the mice muscle.Methods: C57BL/6J mice were randomly divided into 4 groups: ①HF, mice on high fat diet; ② G + F, supplemented with glutamine after 3 months on high fat diet; ③Gln, high fat with glutamine;④Control,normal diet. Each group has been on the diet for 5.5 months. RT-PCR was used to determine the mRNA levels of insulin receptor (IR), insulin receptor substrate-1(IRS-1), insulin receptor substrate-2(IRS-2) and phosphatidylinositol 3-kinase(PI-3-ki- nase). Results: The results showed that the mRNA levels of IR, IRS-1, IRS-2 and PI-3 kinase of the mice on high fat diet were lowered to some degree, they were 81%,63%,59% and 45% of that of control respectively. Cnoclusion: Glutamine can prevent reduction of the mRNA level with the above-mentioned genes in fat group. The results suggest that nutrients may influence insulin sensitivity through regulation of gene expression.展开更多
In order to investigate the effects of transmembranous conduction of signals on insulin resistance after scalding,the changes of the binding capacity of insulin receptors in the cell membrane of hepatocytes and the ac...In order to investigate the effects of transmembranous conduction of signals on insulin resistance after scalding,the changes of the binding capacity of insulin receptors in the cell membrane of hepatocytes and the activities of adenylate cyclase were observed in rats after they were inflicted with 30% TBSA full thickness scalding. It was found that the maximum binding capacity of insulin receptors was significantly decreased after scalding but the average affinity increased. The sensitivity of insulin inhibition on the activity of adenylate cyclase was significantly reduced but there was no apparent difference of the maximum inhibition activity. These findings suggest that the impairment of transmembranous conduction of insulin signals across the cell membrane of hepatocytes after scalding can result in abnormal metabolism of glucose and consequently insulin resistance.展开更多
After the rats were inflicted with 30% TBSA full thickness scalding on their back, the changes of insulin receptor tyrosine protein kinase (IRTPK) were studied on the 4th day postscalding with the phosphorylation of ...After the rats were inflicted with 30% TBSA full thickness scalding on their back, the changes of insulin receptor tyrosine protein kinase (IRTPK) were studied on the 4th day postscalding with the phosphorylation of exogenous substrates stimulated with hepatic and muscular plasma membrane in order to explore the possible molecular mechanism of insulin resistance after thermal injury. It was found that insulin resistance appeared in the early stage postscalding while the basic value of phosphorylation of exogenous substrates stimulated with hepatic and muscular plasma membrane was increased and the activity of IPTPK to insulin stimulation was greatly suppressed as compared with the control. These facts suggest that the impaired responses of IRTPK to insulin stimulation may affect the down-stream signal transmission of the insulin receptors and then the signal coupling pathwayfor glucose transmembranous transportation and glycogen synthesis mediated by IRTPK is obstructed and insulinresistance develops.展开更多
The binding activity of insulin receptors, the insulin effects on low Km-cAMP phosphodiesterase (cAMP-PDE) and the level of free fatty acid and cAMP in the adipose tissue were observed on the 4th day after the rats we...The binding activity of insulin receptors, the insulin effects on low Km-cAMP phosphodiesterase (cAMP-PDE) and the level of free fatty acid and cAMP in the adipose tissue were observed on the 4th day after the rats were inflicted with 30% TBSA full thickness scalding. It was found that the maximal binding capacity of the insulin receptors was greatly reduced, and the sensitivity of low Km-cAMP-PDE to insulin decreased. Although the maximal responsiveness was not apparently altered, the dose-response curve was shifted to the right and ED50 increased. The level of free fatty acid and cAMP was not significantly changed in the adipose tissue,These findings indicate that the antilipolytic effect of superphysiological dosage of insulin does not change after scalding.展开更多
To clarify the mechanism and molecular basis of insulin resistance after severe scalding.Methods: In the rats inflicted with 30% TBSA full-thickness scalding, the insulin receptors on the cell membrane of the liver an...To clarify the mechanism and molecular basis of insulin resistance after severe scalding.Methods: In the rats inflicted with 30% TBSA full-thickness scalding, the insulin receptors on the cell membrane of the liver and skeletal muscle were partially purified with WGA-Sepharose 4B affinity chromatography and then the changes of autophosphorylation of insulin receptor β-subunit and the activity of tyrosine protein kinase of insulin receptors IR-TPK were observed with SDS-PAGE and autoradiography of phosphorylation of insulin receptors and phosphorylation of exogenous substrate. Results: The degree of autophosphorylation of insulin receptor β-subunit and the activity of TPK-IR and its sensitivity to insulin stimulation in the liver and skeletal muscle were markedly decreased as compared with the control. Conclusion: The defect of insulin receptor signal transduction may be the molecular basis of insulin resistance after thermal injury.展开更多
目的分析2型糖尿病患者血清肿瘤坏死因子受体相关因子3(TRAF3)的表达水平与胰岛功能和胰岛素抵抗(IR)的相关性。方法选取2022年8月至2023年12月收治的148例2型糖尿病患者,根据胰岛素抵抗指数(HOMA-IR)值分为无IR组75例和IR组73例;另选8...目的分析2型糖尿病患者血清肿瘤坏死因子受体相关因子3(TRAF3)的表达水平与胰岛功能和胰岛素抵抗(IR)的相关性。方法选取2022年8月至2023年12月收治的148例2型糖尿病患者,根据胰岛素抵抗指数(HOMA-IR)值分为无IR组75例和IR组73例;另选80例同期体检健康者作为对照组。酶联免疫吸附法测定血清TRAF3的表达水平;Pearson和Spearman法分析血清TRAF3表达水平与空腹胰岛素(FINS)、餐后2 h血糖(2 h PG)、胰岛β细胞功能指数(HOMA-β)、胰岛素敏感指数(ISI)相关性;多元线性回归分析2型糖尿病患者发生IR的影响因素;受试者工作特征(ROC)曲线分析血清TRAF3表达水平对2型糖尿病患者IR的预测价值。结果2型糖尿病患者血清TRAF3水平高于体检健康者,无IR组患者血清TRAF3水平低于IR组(P<0.01)。2型糖尿病患者无IR组和IR组FINS、三酰甘油、低密度脂蛋白胆固醇(LDL-C)、糖化血红蛋白(HbA1c)、空腹血糖(FPG)、2 h PG、HOMA-IR、HOMA-β、ISI比较差异有统计学意义(P<0.05,P<0.01);2型糖尿病患者血清TRAF3水平与FINS、2 h PG、HOMA-β、FPG呈显著正相关(P<0.05);多元线性回归分析结果显示,TRAF3、FINS、FPG、2 h PG、LDL-C、HbA1c均为2型糖尿病患者IR的影响因素(P<0.05,P<0.01);ROC曲线分析结果显示,血清TRAF3表达水平评估2型糖尿病患者IR的曲线下面积为0.818,敏感度和特异度分别为78.08%和73.00%。结论血清TRAF3表达水平与2型糖尿病患者胰岛功能和IR密切相关。展开更多
目的:探讨石榴花水提物(pomegranate flower water extract,PFW)对2型糖尿病小鼠肝脏胰岛素信号传导的影响及机制。方法:将C57BL/6J随机分为正常组、模型组、二甲双胍组(Met)、石榴花水提物低剂量组(PFWL)和石榴花水提物高剂量组(PFWH)...目的:探讨石榴花水提物(pomegranate flower water extract,PFW)对2型糖尿病小鼠肝脏胰岛素信号传导的影响及机制。方法:将C57BL/6J随机分为正常组、模型组、二甲双胍组(Met)、石榴花水提物低剂量组(PFWL)和石榴花水提物高剂量组(PFWH)。连续给药11周后,称小鼠体质量,检测空腹血糖(FBG)、胰岛素(INS)、甘油三酯(TG)和总胆固醇(TC)的含量,计算胰岛素抵抗指数(HOMA-IR);苏木素-伊红(HE)染色观察肝组织病理变化;Western blot法检测肝组织中胰岛素受体底物1(IRS1)、p-IRS1(Ser307)、蛋白激酶B(AKT)、p-AKT(Ser473)、糖原合成酶激酶-3β(Gsk3β)、p-Gsk3β(S9)、芳香烃受体(AhR)、磷脂酰乙醇胺N-甲基转移酶(PEMT)、Bcl-2/腺病毒E1B-19kDa相互作用蛋白3(BNIP3)蛋白表达。结果:与模型组比较,PFWH组FBG、INS、HOMA-IR、TG和TC含量极显著降低(P<0.01);PFWH组小鼠肝细胞内脂肪滴明显减少;PFWH组极显著升高肝脏中IRS1、p-AKT(Ser473)/AKT、p-Gsk3β(S9)/Gsk3β、BNIP3蛋白表达(P<0.01),极显著降低p-IRS1(Ser307)/IRS1、AHR、PEMT蛋白表达(P<0.01)。结论:PFW可能通过调节AHR/BNIP3抑制肝脏脂质沉积,改善p-IRS1(Ser307)/p-AKT(Ser473)/p-GSK3β(S9)胰岛素信号通路转导。展开更多
文摘Objective: To investigate the influence of nutrients on the expression of insulin receptor and its related substrate genes in the mice muscle.Methods: C57BL/6J mice were randomly divided into 4 groups: ①HF, mice on high fat diet; ② G + F, supplemented with glutamine after 3 months on high fat diet; ③Gln, high fat with glutamine;④Control,normal diet. Each group has been on the diet for 5.5 months. RT-PCR was used to determine the mRNA levels of insulin receptor (IR), insulin receptor substrate-1(IRS-1), insulin receptor substrate-2(IRS-2) and phosphatidylinositol 3-kinase(PI-3-ki- nase). Results: The results showed that the mRNA levels of IR, IRS-1, IRS-2 and PI-3 kinase of the mice on high fat diet were lowered to some degree, they were 81%,63%,59% and 45% of that of control respectively. Cnoclusion: Glutamine can prevent reduction of the mRNA level with the above-mentioned genes in fat group. The results suggest that nutrients may influence insulin sensitivity through regulation of gene expression.
文摘In order to investigate the effects of transmembranous conduction of signals on insulin resistance after scalding,the changes of the binding capacity of insulin receptors in the cell membrane of hepatocytes and the activities of adenylate cyclase were observed in rats after they were inflicted with 30% TBSA full thickness scalding. It was found that the maximum binding capacity of insulin receptors was significantly decreased after scalding but the average affinity increased. The sensitivity of insulin inhibition on the activity of adenylate cyclase was significantly reduced but there was no apparent difference of the maximum inhibition activity. These findings suggest that the impairment of transmembranous conduction of insulin signals across the cell membrane of hepatocytes after scalding can result in abnormal metabolism of glucose and consequently insulin resistance.
文摘After the rats were inflicted with 30% TBSA full thickness scalding on their back, the changes of insulin receptor tyrosine protein kinase (IRTPK) were studied on the 4th day postscalding with the phosphorylation of exogenous substrates stimulated with hepatic and muscular plasma membrane in order to explore the possible molecular mechanism of insulin resistance after thermal injury. It was found that insulin resistance appeared in the early stage postscalding while the basic value of phosphorylation of exogenous substrates stimulated with hepatic and muscular plasma membrane was increased and the activity of IPTPK to insulin stimulation was greatly suppressed as compared with the control. These facts suggest that the impaired responses of IRTPK to insulin stimulation may affect the down-stream signal transmission of the insulin receptors and then the signal coupling pathwayfor glucose transmembranous transportation and glycogen synthesis mediated by IRTPK is obstructed and insulinresistance develops.
文摘The binding activity of insulin receptors, the insulin effects on low Km-cAMP phosphodiesterase (cAMP-PDE) and the level of free fatty acid and cAMP in the adipose tissue were observed on the 4th day after the rats were inflicted with 30% TBSA full thickness scalding. It was found that the maximal binding capacity of the insulin receptors was greatly reduced, and the sensitivity of low Km-cAMP-PDE to insulin decreased. Although the maximal responsiveness was not apparently altered, the dose-response curve was shifted to the right and ED50 increased. The level of free fatty acid and cAMP was not significantly changed in the adipose tissue,These findings indicate that the antilipolytic effect of superphysiological dosage of insulin does not change after scalding.
文摘To clarify the mechanism and molecular basis of insulin resistance after severe scalding.Methods: In the rats inflicted with 30% TBSA full-thickness scalding, the insulin receptors on the cell membrane of the liver and skeletal muscle were partially purified with WGA-Sepharose 4B affinity chromatography and then the changes of autophosphorylation of insulin receptor β-subunit and the activity of tyrosine protein kinase of insulin receptors IR-TPK were observed with SDS-PAGE and autoradiography of phosphorylation of insulin receptors and phosphorylation of exogenous substrate. Results: The degree of autophosphorylation of insulin receptor β-subunit and the activity of TPK-IR and its sensitivity to insulin stimulation in the liver and skeletal muscle were markedly decreased as compared with the control. Conclusion: The defect of insulin receptor signal transduction may be the molecular basis of insulin resistance after thermal injury.
文摘目的分析2型糖尿病患者血清肿瘤坏死因子受体相关因子3(TRAF3)的表达水平与胰岛功能和胰岛素抵抗(IR)的相关性。方法选取2022年8月至2023年12月收治的148例2型糖尿病患者,根据胰岛素抵抗指数(HOMA-IR)值分为无IR组75例和IR组73例;另选80例同期体检健康者作为对照组。酶联免疫吸附法测定血清TRAF3的表达水平;Pearson和Spearman法分析血清TRAF3表达水平与空腹胰岛素(FINS)、餐后2 h血糖(2 h PG)、胰岛β细胞功能指数(HOMA-β)、胰岛素敏感指数(ISI)相关性;多元线性回归分析2型糖尿病患者发生IR的影响因素;受试者工作特征(ROC)曲线分析血清TRAF3表达水平对2型糖尿病患者IR的预测价值。结果2型糖尿病患者血清TRAF3水平高于体检健康者,无IR组患者血清TRAF3水平低于IR组(P<0.01)。2型糖尿病患者无IR组和IR组FINS、三酰甘油、低密度脂蛋白胆固醇(LDL-C)、糖化血红蛋白(HbA1c)、空腹血糖(FPG)、2 h PG、HOMA-IR、HOMA-β、ISI比较差异有统计学意义(P<0.05,P<0.01);2型糖尿病患者血清TRAF3水平与FINS、2 h PG、HOMA-β、FPG呈显著正相关(P<0.05);多元线性回归分析结果显示,TRAF3、FINS、FPG、2 h PG、LDL-C、HbA1c均为2型糖尿病患者IR的影响因素(P<0.05,P<0.01);ROC曲线分析结果显示,血清TRAF3表达水平评估2型糖尿病患者IR的曲线下面积为0.818,敏感度和特异度分别为78.08%和73.00%。结论血清TRAF3表达水平与2型糖尿病患者胰岛功能和IR密切相关。
文摘目的:探讨石榴花水提物(pomegranate flower water extract,PFW)对2型糖尿病小鼠肝脏胰岛素信号传导的影响及机制。方法:将C57BL/6J随机分为正常组、模型组、二甲双胍组(Met)、石榴花水提物低剂量组(PFWL)和石榴花水提物高剂量组(PFWH)。连续给药11周后,称小鼠体质量,检测空腹血糖(FBG)、胰岛素(INS)、甘油三酯(TG)和总胆固醇(TC)的含量,计算胰岛素抵抗指数(HOMA-IR);苏木素-伊红(HE)染色观察肝组织病理变化;Western blot法检测肝组织中胰岛素受体底物1(IRS1)、p-IRS1(Ser307)、蛋白激酶B(AKT)、p-AKT(Ser473)、糖原合成酶激酶-3β(Gsk3β)、p-Gsk3β(S9)、芳香烃受体(AhR)、磷脂酰乙醇胺N-甲基转移酶(PEMT)、Bcl-2/腺病毒E1B-19kDa相互作用蛋白3(BNIP3)蛋白表达。结果:与模型组比较,PFWH组FBG、INS、HOMA-IR、TG和TC含量极显著降低(P<0.01);PFWH组小鼠肝细胞内脂肪滴明显减少;PFWH组极显著升高肝脏中IRS1、p-AKT(Ser473)/AKT、p-Gsk3β(S9)/Gsk3β、BNIP3蛋白表达(P<0.01),极显著降低p-IRS1(Ser307)/IRS1、AHR、PEMT蛋白表达(P<0.01)。结论:PFW可能通过调节AHR/BNIP3抑制肝脏脂质沉积,改善p-IRS1(Ser307)/p-AKT(Ser473)/p-GSK3β(S9)胰岛素信号通路转导。
