Effects of magnesium intake on expression of insulin receptor in type 2 diabetes rats

目的观察补镁对2型糖尿病大鼠胰岛素受体(InSulIn rECEPTOr,Ir)表达水平的影响。方法将高脂饲料喂养加链脲佐菌素注射方法诱发的2型糖尿病大鼠随机分为4个组,高、中、低剂量组在高脂饲料中分别加入氧化镁2000、1000、200Mg/kg(以镁离子计),糖尿病对照组只喂饲高脂饲料,正常对照组喂饲普通饲料。动物自由进食,连续4周,用葡萄糖氧化酶法测定空腹尾尖血的血糖含量,腹主动脉取血用放免法测定血清胰岛素含量,用免疫组化法测定胰腺和骨骼肌组织Ir表达水平。结果经IMAgE-PrO PluS图像分析,高剂量组的胰腺和骨骼肌组织中Ir表达水平分别为0.341±0.001和0.346±0.002,均较糖尿病对照组升高,而血糖水平则较糖尿病对照组降低,差异均有显著性意义(P<0.05)。结论镁补充可以提高2型糖尿病大鼠胰腺和骨骼肌组织中Ir的表达水平,降低空腹血糖水平。Objective To investigate the effects of magnesium intake on expression of insulin receptor in type 2 diabetes rats.Methods The models of type 2 diabetes rats were established by feeding with high-fat-diet and injecting streptozotocin(STZ).Rats were randomly assigned to four groups.The high-fat-diets were administrated magnesium at a dose of 2000(high magnesium group),1000(medium magnesium group)and200(low magnesium group).Model control group was only fed with high-fat-diet.Normal control group was fed with common diet.Rats ate freely for four weeks.Fasting blood glucose was detected by glucose oxidase method..Insulin was detected by radio-immunity method.The expression levels of IR of pancreas and skeletal muscle were detected by immunohistochemistry method.Results The immunohistochemistry pictures were analyzed by Image-Pro Plus.Compared with model control group,the expression levels of IR of pancreas and skeletal muscle were 0.341±0.001 and 0.346±0.002,increased and fasting blood glucose decreased significantly in high magnesium group(P<0.05).Conclusion Magnesium intake may increase the expression levels of IR of pancreas and skeletal muscle,and decrease fasting blood glucose in type 2 diabetes rats

The Influence of Magnesium Supplementation on Glucose and Lipid Metabolism of Rats with Type 2 Diabetes Mellitus

目的:研究镁补充对2型糖尿病大鼠糖脂代谢的影响。方法:将用高脂饮食联合链脲佐菌素(STz)方法诱发的2型糖尿病大鼠随机分为四个组,糖尿病对照组喂饲高脂饲料,高、中、低剂量组在高脂饲料中分别加入2000、1000、200 Mg/kg的镁(以镁离子计)。自由饮食喂养四周,处死动物。用放射免疫法测血清胰岛素(InS)水平、用葡萄糖氧化酶法测空腹血浆葡萄糖(fASTIng PlASMAgluCOSE,fPg),并计算胰岛素敏感指数(InSulIn SEnSITIVITy IndEX,ISI)。比色法检测糖化血红蛋白(glyCOSylATEd HEMOglObIn,HbA1C)。用全自动生化分析仪测高密度脂蛋白胆固醇(HIgH-dEnSITy lIPOPrOTEIn CHOlESTErOl,HdlC)、甘油三酯(TrIglyCErIdE,Tg)、总胆固醇(TOTAl CHOlESTErOl,TC)。结果:高剂量组的空腹血糖、空腹血清、糖化血红蛋白、甘油三酯、总胆固醇水平均较糖尿病对照组显著性降低(P<0.05),而高密度脂蛋白胆固醇、胰岛素敏感指数较糖尿病对照组显著性升高(P<0.05)。结论:镁补充可以提高2型糖尿病大鼠胰岛素敏感性,改善糖尿病大鼠的糖脂代谢情况。Objective: To investigate the effect of magnesium supplementation on glucose and lipid metabolism of rats with type 2 diabetes mellitus.Method: Rats with type 2 diabetes mellitus were induced with high fat diet and intraperitoneal injection with small dose of STZ,then they were divided into 4 groups randomly: high,medium,low magnesium supplementation groups and diabetes mellitus control group.Diabetes mellitus control group was feed with high-fat feed only.The dosage added in high-fat feed of the high,medium,low magnesium supplementation groups are 2000,1000,200 mg/kg(measured by Mg2+).All the rats ate and drunk freely.All rats were killed after four weeks.The serum insulin(Ins) level were tested with radiation immune method,fasting plasma glucose(FPG)were mea-sured with glucose oxidase method,and calculation the insulin sensitivity index(ISI).Glycosylated hemoglobin(HbA1c) was measured by chromatometry.High-density lipoprotein cholesterol(HDLC),triglyceride(TG),total cholesterol(TC) were measured by automatic biochemical analyzer.Results: FPG,Ins,TG,TC levels of high dose group was significantly lower compared with that in the diabetic control group(P<0.05),while HDLC,ISI increased significantly compared with that in the diabetic control group(P<0.05).Conclusion: Magnesium supplement can improve insulin sensitivity,improve glucose and lipid metabolism in type 2 diabetic rats

INFLUENCE of MAGNESIUM SUPPLEMENTATION ON INSULIN RESISTANCE AND THE INFINITY of RECEPTOR IN RATS WITH TYPE 2 DIABETES MELLITUS

目的观察镁补充对2型糖尿病大鼠胰岛素受体亲和力的影响。方法将用高脂饮食联合链脲佐菌素(STz)方法诱发的2型糖尿病大鼠随机分为4个组,糖尿病对照组喂饲高脂饲料,高、中、低剂量组在高脂饲料中分别加入2000、1000、200Mg/kg的镁(以镁离子计)。每周检测空腹血糖1次。自由饮食喂养4 W,处死动物。用放射性受体分析法测肝细胞胰岛素受体亲和力、放射免疫法测血清胰岛素(InS)水平、比色法检测糖化血红蛋白(HbA1C)和血浆丙二醛(MdA)、葡萄糖氧化酶法测空腹血浆葡萄糖(fPg),并计算胰岛素敏感指数(ISI)和抵抗指数(IrI)。结果高剂量组的高亲和力胰岛素受体结合常数(k1)为(4.76±0.08)x108l/MOl,低亲和力胰岛素受体结合常数(k2)与结合容量(r2)分别为(1.10±0.14)x106l/MOl,(8.49±0.43)x1013/Mg蛋白,均较糖尿病对照组显著性升高(P<0.05)。补镁第3 W开始高剂量组空腹血糖较糖尿病对照组显著性降低,高剂量组的胰岛素敏感指数较糖尿病对照组显著性升高,而胰岛素抵抗指数则显著性降低。结论镁补充可以提高2型糖尿病大鼠胰岛素受体亲和力,降低胰岛素抵抗。Objective To observe the influence of magnesium supplementation on the infinity of insulin receptor in rats with type 2 diabetes mellitus.Method The rats with type 2 diabetes mellitus were induced with high fat diet and intraperitoneal injection with small dose of STZ.They were randomly divided into 4 groups,i.e.high,medium,low magnesium(2000,1000,200 mg/kg Mg2+) supplementation groups and diabetes mellitus control group.FPG was measured weekly.All rats were killed after 4 w,and liver cells were tested with radiation receptor analysis of their combination constants and combined capacity.The serum insulin(Ins) level was determined with radioimmunoassay.FPG,glycosylated hemoglobin(HbA1c) and plasma malondialdehyde(MDA) were also measured,and insulin resistance index(IRI) and insulin sensitivity index(ISI) were calculated.Results: High affinity insulin receptor combination constant(K1),low affinity insulin receptor combination constant(K2) and combination capacity(R2) of high dosage group were(4.76±0.08)×108 L/ mol,(1.10±0.14)×106 L/ mol,(8.49±0.43)×1013 /mg protein respectively,significantly increased than those in diabetes mellitus control group(P<0.05).FPG was decreased since the 3th week during magnesium supplementation.The insulin sensitivity index(ISI) of high dosage group was significantly increased than that of model control group,but insulin resistance index(IRI) was decreased.Conclusion Magnesium supplementation could improve insulin receptor affinity and reduce insulin resistance in type 2 diabetic rats

EFFECTS of MAGNESIUM INTAKE ON ANTI-OXIDATIVE ACTIVITY IN RATS WITH TYPE-2 DIABETIC RATS

目的观察补镁对2型糖尿病大鼠抗氧化能力和糖脂代谢的影响。方法高脂饲料喂养加链脲佐菌素注射方法制备2型糖尿病大鼠模型,然后氧化镁高、中、低剂量组在高脂饲料中分别加入氧化镁2 000、1 000、200Mg/kg(以镁离子计)喂饲,糖尿病组只喂饲高脂饲料,正常对照组喂饲普通饲料。动物自由进食,连续4周,采用葡萄糖氧化酶法测定大鼠空腹尾尖血的血糖含量,腹主动脉取血测定空腹三酰甘油(Tg)、血镁、胰岛素、总抗氧化能力(T-AOC)、超氧化物歧化酶(SOd)及丙二醛(MdA)水平。结果与糖尿病组比较,氧化镁高剂量组SOd和T-AOC水平显著升高,而MdA、空腹血糖和Tg水平明显降低,差异均有显著性(f=9.96~41.05,T=2.55~29.27,P<0.05)。结论补充镁可以提高2型糖尿病大鼠抗氧化能力,改善糖脂代谢。Objective To investigate the effect of magnesium intake on anti-oxidative activity and glucolipid metabolism in type-2 diabetic rats.MethodsA model of type-2 diabetes was created in rats by feeding with high fat forage plus injection of streptozotocin.The rats in high-fat-diet groups were given magnesium oxide at a dose of 2 000,1 000 and 200 mg/kg(based on magnesium ion) to rats in high-,median-and low-magnesium-oxide group.For those in model group,high fat diet only was given,those in the control group,fed with ordinary forage only.All the rats took food unconventionally for four weeks.Fasting blood glucose in tail ending was detected by glucose oxidase method.The blood taken from abdominal aorta was used to measure fasting triacylglycerol(TG),the levels of magnesium,insulin,total antioxidative capability(T-AOC),superoxide dismutase(SOD) and malondialdehyde(MDA).ResultsCompared with the model group,SOD and T-AOC in high-magnesium-oxide group obviously increased,and MDA,blood glucose and TG decreased(F=9.96-41.05,t=2.55-29.27,P<0.05).ConclusionSupplementary of magnesium may increase anti-oxidative activityin rats with type-2 diabetes,and improve glucolipid metabolism