论文部分内容阅读
目的研究茶多糖(TP)对四氧嘧啶糖尿病小鼠糖代谢、组织形态学及胰岛β细胞超微结构的影响及其调节血糖的作用机制。方法将四氧嘧啶诱导的糖尿病小鼠随机分成4组对照组,低、中、高剂量TP组,每天分别灌胃给予蒸馏水、TP0.25、0.50、1.00g/(kgbw),连续5w,每周称重一次。在实验2w末、4w末各测空腹血糖一次。实验末期进行糖耐量实验;取股动脉血测血清胰岛素含量;取适量肝脏测肝糖元含量;制成10%肝匀浆测蛋白含量、己糖激酶(HK)、丙酮酸激酶(PK)活力;留取肝脏、胰腺、肾脏和脾脏做病理组织学检查;每组随机取5只小鼠胰腺做超薄切片、电镜观察。结果TP能明显缓解糖尿病小鼠症状;三个剂量组空腹血糖值均明显降低(P<0.05或P<0.01),糖耐量实验结果血糖曲线下面积下降,并存在剂量-反应关系。随着TP剂量的增高,血清胰岛素、肝糖元含量均明显增高,肝HK、PK活力均明显增强,以上各项指标均存在一定的剂量-反应关系。与对照组比,TP组肝细胞变性程度有所减轻,中、高剂量组肝组织病理变化总分均明显减少(P=0.000),胰岛数量明显恢复、体积增大,胰岛细胞明显修复、再生。三个剂量组小鼠胰岛数量明显高于对照组(P<0.05或P<0.01);胰岛β细胞内质网、线粒体等结构的损伤得到明显修复,酶原颗粒明显增多,细胞分泌等功能明显改善和恢复。结论TP能调节糖代谢,降低血糖,改善糖尿病小鼠的症状。
Objective To investigate the effects of tea polysaccharide (TP) on glycometabolism, histomorphology and islet β cell ultrastructure in alloxan diabetic mice and its mechanism of regulating blood glucose. Methods Alloxan-induced diabetic mice were randomly divided into 4 groups: control group, low, middle and high dose of TP group. The rats were given gavage with TP 0.25, 0.50, 1.00 g / (kg bw) Week weighing again. In the end of the experiment 2w, 4w at the end of each test fasting blood glucose once. Glucose tolerance test was performed at the end of the experiment. Serum insulin was taken from the femoral artery. The content of hepatic glycogen in the liver was measured. The protein content, hexokinase (HK), pyruvate kinase (PK) activity Liver, pancreas, kidney and spleen were removed for histopathological examination. The pancreas of 5 mice in each group were made into ultrathin section and electron microscopy. Results TP could relieve the symptoms of diabetic mice. The fasting blood glucose of the three dosage groups were significantly lower (P <0.05 or P <0.01). The results of glucose tolerance test showed that the area under the blood glucose curve decreased and there was a dose-response relationship. With the increase of TP dose, the levels of serum insulin and hepatic glycogen were significantly increased, and the activities of liver HK and PK were significantly increased. All the above indexes had some dose-response relationship. Compared with the control group, the degree of hepatocellular degeneration in TP group was alleviated. The total pathological changes of liver tissue in middle and high dose groups were significantly decreased (P = 0.000), the number of islets recovered obviously, the volume increased, the islet cells were obviously repaired and regenerated . The number of pancreatic islets in the three dose groups was significantly higher than that in the control group (P <0.05 or P <0.01). The damage of endoplasmic reticulum, mitochondria and other structures of islet β cells was obviously repaired, the number of zygote granules increased significantly and the function of cell secretion was obvious Improve and recover. Conclusion TP can regulate glucose metabolism, lower blood sugar and improve the symptoms of diabetic mice.