【作者】 马慧；

【导师】 宋志民； 王文汇；

【作者基本信息】 山东大学 ， 内分泌与代谢病， 2007， 硕士

【摘要】 目的：检测2型糖尿病大鼠、单纯肥胖大鼠及正常大鼠空腹血清Ghrelin、Visfatin水平，分析两因子相关性及其与体重、大鼠肥胖指数、内脏脂肪含量、血糖、胰岛素及脂代谢紊乱的关系，并探讨两因子与胰岛素敏感指数的关系；检测ghrelin在大鼠胃部、visfatin在大鼠内脏脂肪中的表达，分析两者与2型糖尿病的关系。方法：(1)采用高糖高脂饮食12周+小剂量链脲佐菌素(STZ)诱导雄性Wister大鼠，制备2型糖尿病组大鼠模型；同时采用高糖高脂饮食12周制备单纯肥胖组大鼠模型；并设定正常大鼠为对照组。(2) 2型糖尿病组(18只)、单纯肥胖组(15只)及对照组(10只)为研究对象，标准方法测量大鼠体重，身长，内脏脂肪含量，计算肥胖评定指数；酶联免疫方法(EIA)测定空腹血清ghrelin、visfatin浓度，并测定空腹血糖、甘油三酯、总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、糖化血红蛋白、胰岛素，计算胰岛素敏感指数。(3)免疫组织化学方法观察ghrelin在大鼠胃部和visfatin在大鼠内脏脂肪的表达，通过灰度测量比较三组大鼠胃部ghrelin、内脏脂肪组织visfatin表达的差异。结果：(1)高糖高脂饮食12周+STZ(35mg／kg)的大鼠，进食量、饮水量、尿量、体重、肥胖指数、空腹血脂、胰岛素均较正常大鼠增加，胰岛素敏感性较正常组降低，且死亡率小，成模率高，可作为实验型2型糖尿病大鼠模型；单纯高糖高脂饮食12周的大鼠，进食量、体重肥胖指数、血清胰岛素较正常组增加，而胰岛素敏感性降低，可作为实验型单纯肥胖大鼠模型。(2)糖尿病组(18.26±6.42pg／ml)和单纯肥胖组(15.57±5.23pg／ml)空腹血清Ghrelin浓度与对照组(31.73±7.18pg／ml)有显著统计学差异(p＜0.01)。(3)糖尿病组(26.38±12.74ng／ml)和单纯肥胖组(35.42±15.76ng／ml)空腹血清Visfatin浓度与对照组(16.32±10.38ng／ml)有统计学差异(p＜0.05)。(4) Pearson相关分析表明：2型糖尿组大鼠空腹血清Ghrelin与Lee index、体脂含量、FBG、FINS呈显著负相关(r=-0.673，p＜0.001；r=-0.415，p=0.004；r=-0.228，p=0.02；r=-0.427，p=0.004)，与ISI、HDL-c呈显著正相关(r=0.329，p=0.005；r=0.354，p=0.005)；单纯肥胖组空腹血清Ghrelin与Lee index、体脂含量、FINS呈显著负相关(r=-0.846，p＜0.001；r=-0.362，p=0.009；r=-0.312，p=0.07；)，与ISI、HDL-c呈显著正相关(r=0.376，p=0.006；r=0.298，p=0.043)；对照组空腹血清Ghrelin与Lee index、体脂含量呈显著负相关(r=-0.425，p=0.003；r=-0.265，p=0.038)。(5) Pearson相关分析表明：2型糖尿病大鼠空腹血清Visfatin与内脏脂肪含量、FBG呈显著正相关(r=0.415，p＜0.001；r=0.259，p=0.035)，与HDL—c呈显著负相关(r=-0.285，p=0.031)；单纯肥胖组大鼠空腹血清Visfatin与Lee index、体脂含量呈显著正相关(r=0.328，p=0.010；r=0.498，p＜0.001)；对照组空腹血清Visfatin与体脂含量、TG呈显著正相关(r=0.456，p=0.003；r=0.317，p=0.038)。(6) Pearson相关分析表明在三组大鼠中ghrelin与visfatin之间均无统计学相关性。(7)多元逐步回归分析显示大鼠肥胖指数是2型糖尿病大鼠和单纯肥胖大鼠空腹血清Ghrelin水平的主要变量(r=-0.673，p＜0.001；r=-0.846，p＜0.001)，内脏脂肪含量是2型糖尿病大鼠和单纯肥胖大鼠空腹血清Visfatin水平的主要变量(r=0.415，p＜0.001；r=0.498，p＜0.001)。(8)2型糖尿病大鼠和单纯肥胖大鼠胃部ghrelin表达与正常大鼠有显著差异，且与血清ghrelin水平呈正相关，；2型糖尿病和单纯肥胖大鼠内脏脂肪visfatin表达与正常大鼠有显著差异，且与血清visftain水平呈正相关。结论：(1) 2型糖尿病大鼠和单纯肥胖大鼠空腹血清Ghrelin水平均降低，visfatin水平均升高。2型糖尿病大鼠和单纯肥胖大鼠中，大鼠肥胖指数是空腹血清Ghrelin水平的独立影响因子，内脏脂肪含量是空腹血清visfatin水平的独立影响因子。提示ghrelin、visfatin对胰岛素敏感性的影响主要通过肥胖起作用。(2) Ghrelin、Visfatin的分泌调节和生理作用无密切关系。(3) 2型糖尿病大鼠和单纯肥胖大鼠胃部ghrelin表达较正常大鼠降低，内脏脂肪visfatin表达水平升高，与血清水平变化一致，提示胃部和内脏脂肪组织分别是ghrelin和visfatin的主要分泌部位。更多还原

【Abstract】 Objective: To measure levels of ghrelin and visfatin of fasting serum and tissue in rats with type 2 diabetes mellitus (T2DM) 、 obese rats and normal rat , to study their correlations to insulin sensitivity and type 2 diabetes mellitus.Methods: (1)Use high-sucrose and high-fat diet +STZ inducing wister rats, develop rats model with type 2 diabetes mellitus (T2DM);use only high-sucrose and high-fat diet develop obese rats model. (2)Use enzyme-linked immunoassay (EIA) to measure fasting serum ghrelin and visfatin in 18 type 2 diabetes rats、 15 obese rats and 10 normal rat. The body weight 、 body length and viscus fat weight were recorded, and calculate the lee index. Fasting blood glucose (FBG), triglyceride (TG), total cholesterol(TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), fasting serum insulin (FINS) were measured in all of the subjects, Use Bennett Index to estimate insulin sensitivity. (3) Use immunohistochemistry to measure ghrelin expressive level in stomach and visfatin in viscus fat tissue.Results: (1)Rats Use high-sucrose and high-fat diet (12 weeks)+STZ (35mg/kg) inducing have higher food-intake、 drinking 、 urine volume、 body weight、 lee index、 FBG、 FINS than that of the control, and have lower insulin sensitivity than that of the control.(2) The fasting serum ghrelin was significantly lower in the diabetes rats ( 18.26±6.42pg/ml) and obese rats (15.57±5.23pg/ml) than that of the control (31.73±7.18pg/ml) (p<0.01).(3) The fasting serum ghrelin was significantly higher in the diabetes rats (26.38±12.74ng/ml) and obese rats (35.42±15.76ng/ml) than that of the control(p<0.05).(4) The fasting serum ghrelin of the diabetes rats was negatively correlated with lee index (r=-0.673, p<0.001), viscus fat weight ( r=-0.415, p=0.004), FBG(r=-0.228, p=0.02), FINS(r=-0.427, p=0.004), and it was positively correlated with ISI (r=0.329, p=0.005), HDL-c(r=0.354,p=0.005). The level of ghrelin in obese rats was negatively correlated with lee index (r=-0.846, p<0.001), viscus fat weight ( r=-0.362, p=0.009), FINS(r=-0.312, p=0.07), and it was positively correlated with ISI (r=0.376, p=0.006), HDL-c(r=0.298,p=0.043). The level of ghrelin in control rats was negatively correlated with lee index (r=-0.425, p=0.003), viscus fat weight (r=-0.265, p=0.038).(5) The fasting serum visfatin of the diabetes rats was positively correlated with viscus fat weight ( r=0.415, p<0.001), FBG(r=0.259, p=<0.035), and it was negatively correlated with HDL-c(r=-0.285,p=0.031). The level of ghrelin in obese rats was positively correlated with lee index (r=0.328, p=0.010), viscus fat weight ( r=0.498, p<0.001). The level of ghrelin in control rats was positively correlated with viscus fat weight ( r=0.456, p=0.003), TG(r=0.317, p=0.038).(6) The fasting serum ghrelin and visfatin level was not correlation.(7)After multiple regression analysis, the lee index seemed to be the best variable in predicting diabetes rats and obese rats ghrelin levels(r=-0.673, p<0.001; r=-0.846, p<0.001) ; the viscus fat weight seemed to be the best variable in predicting diabetes rats and obese rats visfatin levels(r=0.415, p<0.001; r=0.498, p<0.001).(8)The ghrelin expressive level in stomach of diabetes rats and obese rats was significantly lower than that of the control; the visfatin expressive level in viscus fat tissue of diabetes rats and obese rats was significantly higher than that of the control, and the ghrelin and visfatin expressive level in tissue was positively correlated with fasting serum level.Conclusion:The fasting serum ghrelin and expressive level in stomach was reduced in the diabetes and obese, and it was significantly associated with ISI. The fasting serum visfatin and expressive level in viscus fat tissue was advanced in the diabetes and obese, and it was not associated with ISI. The lee index is the determinative factor in serum ghrelin level while the viscus fat weight is the determinative factor in serum visfatin level in T2DM . Ghrelin and visfatin effect insulin sensitivity via obese.Stomach and viscus fat tissue is the mainly secrete position of ghrelin and visfatin respective.更多还原