胰高糖素样肽-1受体激动剂对糖尿病大鼠胰岛α细胞形态和功能的影响

发布时间：2018-03-14 08:03

本文选题：Exendin-4　切入点：糖尿病　出处：《济南大学》2015年硕士论文　论文类型：学位论文

【摘要】：目的胰高糖素样肽-1(GLP-1)受体激动剂Exendin-4(EX-4)对2型糖尿病大鼠胰岛α细胞形态和功能的影响目前尚不十分清楚。本研究通过不同浓度的GLP-1受体激动剂EX-4对2型糖尿病大鼠模型进行干预,观察EX-4对2型糖尿病大鼠胰岛α细胞形态与功能的影响,从而为探讨2型糖尿病的病理生理学和临床应用提供新的理论依据。方法采用高糖高脂喂养并联合1%的STZ(35mg/kg)腹腔注射建立T2DM大鼠模型。40只雄性Wistar大鼠随机分为正常对照(NC组,N=10)组和糖尿病组(n=30)。剔除造模失败死亡的大鼠后将剩余25只纳入本实验。分为糖尿病对照组(DC组,n=8),Exendin-4治疗组(EX组,n=17),其中EX低剂量组(EXL组n=8),EX高剂量组(EXH组,n=9)。将Exendin-4溶于PBS溶液,EXL组左下腹腔注射5μg/kg,EXH组20μg/kg,每日定时两次(上午9:00和下午5:00),NC、DC组注射PBS,治疗8周。干预8周后,空腹12h,次日上午于给药0h,1h,2h,3h,后分别颈静脉抽血测血糖,取血清标本用放射免疫法测定血清胰高糖素。剥离胰腺组织,置于中性福尔马林液固定,然后石蜡包埋做切片备用。石蜡切片做HE染色以观察形态学变化,免疫组化法染色观察胰高糖素表达水平,观察α细胞形态及数量变化。结果1.各组大鼠及血清胰高糖素水平干预前,DC组、EXL组及EXH组胰高糖素均较NC组明显升高(P0.01)。干预8周后,EXL组及EXH胰高糖素水平较干预前下降(P0.05),EXH组下降较EXL组显著(P0.05),且低于与同期DC组(P0.01)。2.干预后于末次给药(0h,1h,2h,3h)监测血糖,绘制血糖曲线图DM组、EXH组、EXL组大鼠血糖明显高于DC组,EXH组、EXL组血糖较DM组明显下降(P0.01),EXH组下降幅度较EXL组大,且血糖随时间点增加而下降。3.各组大鼠胰岛α细胞免疫组化染色结果免疫组化法定位胰高糖素,Glucagon蛋白表达在细胞胞浆中,NC组Glucagon蛋白主要分布于胰岛外周的α细胞,且量较少,DC组和EX组Glucagon蛋白除分布在胰岛外周α细胞外,在胰岛中央也多见表达。干预8周后,与NC组相比,DC组和EX组胰高糖素蛋白表达明显增多,其中EX组表达量少于DC组。EXH组表达量少于EXL组。4.各组大鼠胰腺组织HE染色结果NC组胰岛丰富形态饱满,细胞核居中分布在均匀的胞浆中。内分泌部胰岛和外分泌部腺小叶清晰可见。在DC组及实验组中,胰岛排列相对紧密,胰岛间多见管腔内存有红细胞的毛细血管分布。胰岛出现不同程度结构破坏以及脂肪的浸润和慢性炎症的改变。在DC组,上述改变最为显著。与DC组相比,EXL组EXH组上述改变有明显改善,且EXH组改善情况优于EXL组。结论GLP-1受体激动剂Exendin-4能够改善2型糖尿病大鼠胰岛α细胞形态,抑制过度增殖的大鼠胰岛α细胞的数量,抑制其分泌胰高糖素,从而有效降低血糖水平。
[Abstract]:Objective the effect of Exendin-4 (EX-4) on the morphology and function of pancreatic islet 伪 cells in type 2 diabetic rats is not clear. In this study, different concentrations of GLP-1 receptor agonist EX-4 were used to interfere with type 2 diabetic rats. To observe the effect of EX-4 on the morphology and function of islet 伪 cells in type 2 diabetic rats. Therefore, this paper provides a new theoretical basis for the pathophysiology and clinical application of type 2 diabetes mellitus. Methods T2DM rat model. 40 male Wistar rats were randomly divided into normal rats by high glucose and high fat feeding combined with 1% STZ 35 mg / kg intraperitoneal injection. The remaining 25 rats were included in this experiment. The remaining 25 rats were divided into control group (DC group) and exendin-4 treatment group (EX group), among which the low dose group (ex group) and the low dose group (EXL group) were treated with n8EX group, the high dose group (EXH group) was divided into two groups: the control group, the control group, the control group, the control group and the diabetic group, and the remaining 25 rats were included in the experiment. The rats in the control group were divided into two groups: the control group, the DC group and the Exendin-4 treatment group. Exendin-4 dissolved in PBS solution was injected intraperitoneally into the left of the PBS group (5 渭 g / kg) and 20 渭 g / kg in the EXH group at regular intervals twice a day (9:00 in the morning and 5: 00pm in the control group) for 8 weeks. Blood glucose was measured by jugular vein blood sampling and serum samples were measured by radioimmunoassay. Pancreatic tissue was removed and fixed in neutral formalin solution. The paraffin sections were then embedded in paraffin for the preparation of sections. The paraffin sections were stained with HE to observe the morphological changes, and the expression of glucagon was observed by immunohistochemical staining. The changes of 伪 -cell morphology and quantity were observed. 1. The levels of glucagon in rats and serum glucagon in each group were significantly higher than those in NC group before intervention in DC group and EXH group. After 8 weeks of intervention, the levels of glucagon in exl group and EXH group were higher than those in NC group. 2. Compared with EXL group, the decrease of P0.05H group was significantly lower than that of EXL group, and was lower than that of DC group (P0.01U 路2.The blood glucose was monitored at 1 hour or 2 h after the last intervention). The blood glucose of the rats in the exh group was significantly higher than that in the DC group. The blood glucose in the exh group was significantly lower than that in the DM group. The decrease range of blood glucose in the exh group was higher than that in the EXL group. The results of immunohistochemical staining showed that the expression of glucagon protein in the cytoplasm of NC group was mainly distributed in the 伪 cells around the islets. The expression of Glucagon protein was also found in the center of the islet in addition to the peripheral 伪 cells in the DC group and ex group. After 8 weeks of intervention, the expression of glucagon protein in the DC group and ex group was significantly higher than that in the NC group. The expression of exh in the ex group was less than that in the DC group and the exh group was less than that in the EXL group. 4. The results of HE staining showed that the pancreatic islets in the NC group were rich in shape and full in shape. The nucleus was distributed in the uniform cytoplasm. The endocrine islets and the exocrine gland lobule were clearly visible. In DC group and experimental group, the islets were arranged relatively closely. The capillary distribution of red blood cells was found in the lumen of pancreatic islets. The islets were damaged to varying degrees, fat infiltrated and chronic inflammation were changed. Compared with DC group, the above changes in EXH group were significantly improved, and the improvement in EXH group was better than that in EXL group. Conclusion Exendin-4, a GLP-1 receptor agonist, can improve the morphology of islet 伪 cells in type 2 diabetic rats. Inhibiting the proliferation of rat islet 伪 cells and inhibiting the secretion of glucagon can effectively reduce the level of blood glucose.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R587.1

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