Objective: To investigate the changes in glucose transporter-4(Glut-4) mRNA expression in skeletal muscle before and after the thoracic operation and to observe the changes in Glut-4 mRNA expression by preoperative in...Objective: To investigate the changes in glucose transporter-4(Glut-4) mRNA expression in skeletal muscle before and after the thoracic operation and to observe the changes in Glut-4 mRNA expression by preoperative infusion of glucose. Methods: Twelve cases of elective thoracic operation were randomly divided into two groups, namely ordinary group Ⅰ and glucose infusion group Ⅱ. One gram of intercostal muscle was taken while thorax being opened and closed from patients under general anesthesia. Total RNA of the muscle cells was extracted by TRIzol one-step assay. Reverse transcription-competitive polymerase chain reaction (RT-PCR) was used to determine the Glut-4 mRNA amplification products with β-actin mRNA as an internal control. The Glut-4 mRNA expression was expressed by targeted gene /β-actin ×100%. The plasma glucose and insulin levels were determined at the same time.Results: Glut-4 mRNA expression was significantly reduced(P<0.05) and plasma glucose level increased (P<0.05), while thorax was being closed as compared with those while being opened. However, Glut-4 mRNA expression in glucose infusion group Ⅱ was significantly higher than ordinary group Ⅰ (P<0.01) and plasma glucose level in group Ⅱ was lower than group Ⅰ(P<0.05) when thorax was being closed. Conclusion: The results indicate that the synthesis of Glut-4 is suppressed by the surgical stress of thoracic operation under general anesthesia. We found that preoperative infusion glucose can increase Glut-4 mRNA expression at the same surgical stress and relieve postoperative insulin resistance.展开更多
Background The delivery of glucose from the blood to the brain involves its passage across the endothelial cells of the blood-brain barrier （BBB）, which is mediated by the facilitative glucose transporter protein 1 ...Background The delivery of glucose from the blood to the brain involves its passage across the endothelial cells of the blood-brain barrier （BBB）, which is mediated by the facilitative glucose transporter protein 1 （GLUT1）, end then across the neural cell membranes, which is mediated by GLUT3. This study aimed to evaluate the dynamic influence of hyperglycemia on the expression of these GLUTs by measuring their expression in the brain at different blood glucose levels in e rat model of diabetes. This might help to determine the proper blood glucose threshold level in the treatment of diabetic apoplexy. Methods Diabetes mellitus was induced with streptozotocin （STZ） in 30 rats. The rats were randomly divided into 3 groups： diabetic group without blood glucose control （group DM1）, diabetic rats treated with low dose insulin （group DM2） end diabetic rats treated with high dose insulin （group DM3）. The mRNA end protein levels of GLUT1 end GLUT3 were essayed by reverse trenscriptese-polymerese chain reaction （RT-PCR） end immunohistochemistry, respectively. Results Compared with normal control rats, the G/UT1 mRNA was reduced by 46.08%, 29.80%, 19.22% （P〈0.01） in DM1, DM2, end DM3 group, respectively; end the GLUT3 mRNA was reduced by 75.00%, 46.75%, end 17.89% （P〈0.01） in DM1, DM2, end DM3 group, respectively. The abundance of GLUT1 end GLUT3 proteins had negative correlation with the blood glucose level （P〈0.01）. The density of microvessels in the brain of diabetic rats did not change significantly compared with normal rats. Conclusions Chronic hyperglycemia downreguletes G/UT1 end GLUT3 expression at both mRNA end protein levels in the rat brain, which is not due to the decrease of the density of microvessels. The downreguletion of G/UT1 end GLUT3 expression might be the adaptive reaction of the body to prevent excessive glucose entering the cell that may lead to cell damage.展开更多
目的:探讨乳源活性肽β-酪啡肽-7(β-Casomorphin-7,β-CM7)应用于食品时对葡萄糖吸收的影响及其作用机制.方法:选用健康成年SD大鼠,分为对照组(0mol/Lβ-CM7),L低剂量组、M中剂量组、H高剂量组(终浓度分别为7.5×10-7,7.5×10-...目的:探讨乳源活性肽β-酪啡肽-7(β-Casomorphin-7,β-CM7)应用于食品时对葡萄糖吸收的影响及其作用机制.方法:选用健康成年SD大鼠,分为对照组(0mol/Lβ-CM7),L低剂量组、M中剂量组、H高剂量组(终浓度分别为7.5×10-7,7.5×10-6,7.5×10-5mol/L).利用翻转离体小肠囊模型进行实验:(1)葡萄糖氧化酶法测定翻转后小肠内液葡萄糖含量;(2)比色法测定小肠黏膜Na+-K+-ATP酶活力;(3)荧光定量PCR法分析小肠黏膜组织中钠葡萄糖共转运载体(SGLT-1)和葡萄糖协助扩散转运载体(GLUT-2) mRNA的表达.结果:在离体环境下β-CM7在7.5×10-7-7.5×10-5mol/L浓度下对葡萄糖的吸收均有一定的抑制作用(1.09mol/L,1.24mol/L,1.12mol/L vs 1.74mol/L,P=0.01,0.04,0.02),能够降低Na+-K+-ATP酶活力(85.73,112.06,109.68 vs 114.93,P=0.004,0.73,0.54);荧光定量PCR结果发现:与对照组相比,β-CM7能够显著降低SGLT-1及GLUT-2 mRNA水平(0.46,0.58,0.77 vs 1.11,P=0.20,0.05,0.02;0.50,0.66,0.85 vs 1.14,P=0.30,0.14,0.03).结论:β-CM7可以通过降低Na+-K+-ATP酶活力及下调SGLT-1、GLUT-2 mRNA水平,减少大鼠小肠对葡萄糖的吸收.展开更多
文摘Objective: To investigate the changes in glucose transporter-4(Glut-4) mRNA expression in skeletal muscle before and after the thoracic operation and to observe the changes in Glut-4 mRNA expression by preoperative infusion of glucose. Methods: Twelve cases of elective thoracic operation were randomly divided into two groups, namely ordinary group Ⅰ and glucose infusion group Ⅱ. One gram of intercostal muscle was taken while thorax being opened and closed from patients under general anesthesia. Total RNA of the muscle cells was extracted by TRIzol one-step assay. Reverse transcription-competitive polymerase chain reaction (RT-PCR) was used to determine the Glut-4 mRNA amplification products with β-actin mRNA as an internal control. The Glut-4 mRNA expression was expressed by targeted gene /β-actin ×100%. The plasma glucose and insulin levels were determined at the same time.Results: Glut-4 mRNA expression was significantly reduced(P<0.05) and plasma glucose level increased (P<0.05), while thorax was being closed as compared with those while being opened. However, Glut-4 mRNA expression in glucose infusion group Ⅱ was significantly higher than ordinary group Ⅰ (P<0.01) and plasma glucose level in group Ⅱ was lower than group Ⅰ(P<0.05) when thorax was being closed. Conclusion: The results indicate that the synthesis of Glut-4 is suppressed by the surgical stress of thoracic operation under general anesthesia. We found that preoperative infusion glucose can increase Glut-4 mRNA expression at the same surgical stress and relieve postoperative insulin resistance.
文摘Background The delivery of glucose from the blood to the brain involves its passage across the endothelial cells of the blood-brain barrier （BBB）, which is mediated by the facilitative glucose transporter protein 1 （GLUT1）, end then across the neural cell membranes, which is mediated by GLUT3. This study aimed to evaluate the dynamic influence of hyperglycemia on the expression of these GLUTs by measuring their expression in the brain at different blood glucose levels in e rat model of diabetes. This might help to determine the proper blood glucose threshold level in the treatment of diabetic apoplexy. Methods Diabetes mellitus was induced with streptozotocin （STZ） in 30 rats. The rats were randomly divided into 3 groups： diabetic group without blood glucose control （group DM1）, diabetic rats treated with low dose insulin （group DM2） end diabetic rats treated with high dose insulin （group DM3）. The mRNA end protein levels of GLUT1 end GLUT3 were essayed by reverse trenscriptese-polymerese chain reaction （RT-PCR） end immunohistochemistry, respectively. Results Compared with normal control rats, the G/UT1 mRNA was reduced by 46.08%, 29.80%, 19.22% （P〈0.01） in DM1, DM2, end DM3 group, respectively; end the GLUT3 mRNA was reduced by 75.00%, 46.75%, end 17.89% （P〈0.01） in DM1, DM2, end DM3 group, respectively. The abundance of GLUT1 end GLUT3 proteins had negative correlation with the blood glucose level （P〈0.01）. The density of microvessels in the brain of diabetic rats did not change significantly compared with normal rats. Conclusions Chronic hyperglycemia downreguletes G/UT1 end GLUT3 expression at both mRNA end protein levels in the rat brain, which is not due to the decrease of the density of microvessels. The downreguletion of G/UT1 end GLUT3 expression might be the adaptive reaction of the body to prevent excessive glucose entering the cell that may lead to cell damage.
文摘目的:探讨乳源活性肽β-酪啡肽-7(β-Casomorphin-7,β-CM7)应用于食品时对葡萄糖吸收的影响及其作用机制.方法:选用健康成年SD大鼠,分为对照组(0mol/Lβ-CM7),L低剂量组、M中剂量组、H高剂量组(终浓度分别为7.5×10-7,7.5×10-6,7.5×10-5mol/L).利用翻转离体小肠囊模型进行实验:(1)葡萄糖氧化酶法测定翻转后小肠内液葡萄糖含量;(2)比色法测定小肠黏膜Na+-K+-ATP酶活力;(3)荧光定量PCR法分析小肠黏膜组织中钠葡萄糖共转运载体(SGLT-1)和葡萄糖协助扩散转运载体(GLUT-2) mRNA的表达.结果:在离体环境下β-CM7在7.5×10-7-7.5×10-5mol/L浓度下对葡萄糖的吸收均有一定的抑制作用(1.09mol/L,1.24mol/L,1.12mol/L vs 1.74mol/L,P=0.01,0.04,0.02),能够降低Na+-K+-ATP酶活力(85.73,112.06,109.68 vs 114.93,P=0.004,0.73,0.54);荧光定量PCR结果发现:与对照组相比,β-CM7能够显著降低SGLT-1及GLUT-2 mRNA水平(0.46,0.58,0.77 vs 1.11,P=0.20,0.05,0.02;0.50,0.66,0.85 vs 1.14,P=0.30,0.14,0.03).结论:β-CM7可以通过降低Na+-K+-ATP酶活力及下调SGLT-1、GLUT-2 mRNA水平,减少大鼠小肠对葡萄糖的吸收.
