Exendin-4对严重烫伤大鼠早期胰腺损伤的影响与机制研究

发布时间：2018-05-05 12:32

本文选题：Exendin-4 + 烧伤　；参考：《中国人民解放军医学院》2015年硕士论文

【摘要】：目的：烧伤后容易发生以“高糖血症”为表现的糖代谢障碍,容易引起不良预后。研究表明,烧伤后糖代谢障碍与胰腺损伤密切相关。Exendin-4是一种GLP-1受体激动剂,并具有高糖依赖的胰岛素促泌作用,且不会导致低血糖。近年来研究报道Exendin-4能抑制氧化应激、炎症和凋亡,而目前Exendin-4保护严重烧伤后胰腺损伤的机制尚缺乏研究。因此,本研究拟探讨Exendin-4对严重烫伤大鼠早期胰腺损伤的影响与机制。方法：成年健康Wistar大鼠96只,随机分为假烫组、假烫给药组、烫伤组和烫伤给药组,每组24只。烫伤组和烫伤给药组大鼠背部浸于94。C热水12秒,腹部6秒,制备50%TBSAⅢ°烫伤模型,假烫组和假烫给药组使用37℃温水,其余处理相同。烫伤给药组和假烫给药组伤后立即于皮下注射Exendin-4 (4ug/kg),并于伤后每天8：00和20：00分别给药一次,其它组大鼠同时以相同方式给予相同剂量的灭菌注射用水。伤后1d、3d和5d,剪尾法采血检测各组大鼠空腹血糖浓度；放射免疫法检测血清胰岛素浓度；干湿质量法计算胰腺组织含水量；HE染色观察胰腺形态变化；硫代巴比妥酸法检测胰腺组织丙二醛(MDA)含量；免疫组织化学法分析胰腺诱导性一氧化氮合酶(iNOS)表达水平；免疫印迹法分析胰腺组织3-硝基硝基络氨酸(3-NT)、B细胞淋巴瘤-2相关X蛋白(Bax)蛋白、活化部分半胱氨酸天冬氨酸蛋白酶3(Cleaved caspase-3)表达水平。结果：假烫组和假烫给药组大鼠伤后各时相点空腹血糖浓度均无明显升高或降低；烫伤组大鼠伤后1d、3d和5d空腹血糖浓度显著高于假烫组和假烫给药组；烫伤给药组大鼠伤后1d和3d空腹血糖浓度显著低于烫伤组；烫伤给药组大鼠伤后1d空腹血糖浓度显著高于假烫组和假烫给药组。假烫组和假烫给药组大鼠各时相点空腹血清胰岛素浓度均无明显升高或降低；烫伤组大鼠伤后各时相点空腹血清胰岛素浓度均显著高于假烫组和假烫给药组；烫伤给药组大鼠伤后各时相点空腹血清胰岛素浓度均显著高于烫伤组。假烫组和假烫给药组大鼠伤后各时相点胰腺组织含水量均无明显升高或降低；烫伤组和烫伤给药组大鼠伤后1d胰腺组织含水量显著高于假烫组和假烫给药组；与烫伤组比较,烫伤给药组大鼠胰腺组织含水量无明显升高或降低。HE染色结果显示,假烫组和假烫给药组大鼠伤后各时相点胰岛形态规则,β细胞数量丰富,分布均匀,排列紧密,胞浆浓染,偶见空泡样改变；烫伤组大鼠伤后1d即出现胰岛空泡样变和p细胞数量减少,伤后3d胰岛内出现广泛空泡样变,p细胞数量显著减少,伤后5d胰岛空泡样变轻于伤后3d,β细胞数量多于伤后3d；烫伤给药组大鼠伤后各时相点胰岛空泡样变均轻于烫伤组,β细胞数量均多于烫伤组。假烫组和假烫给药组大鼠伤后各时相点胰腺组织丙二醛(MDA)含量均无明显升高或降低；烫伤组大鼠伤后各时相点胰腺组织丙二醛(MDA)含量均显著高于假烫组和假烫给药组；烫伤给药组大鼠伤后1d和3d胰腺组织丙二醛(MDA)含量均显著高于假烫组和假烫给药组；与烫伤组比较,烫伤给药组大鼠伤后5d胰腺组织丙二醛(MDA)含量低于烫伤组。免疫组化结果显示,假烫组和假烫给药组大鼠伤后各时相点胰岛诱导型一氧化氮合酶(iNOS)表达水平均无明显升高或降低；烫伤组大鼠伤后各时相点胰岛诱导型一氧化氮合酶(iNOS)表达水平均高于假烫组和假烫给药组；烫伤给药组大鼠伤后各时相点胰岛诱导型一氧化氮合酶(iNOS)表达水平均低于烫伤组,高于假烫组和假烫给药组。Western Blot结果显示,假烫组和假烫给药组大鼠伤后各时相点胰腺组织3-硝基酪氨酸(3-NT)蛋白水平表达水平均无明显升高或降低；伤后3d和5d,烫伤组大鼠胰腺组织3-NT蛋白表达水平显著高于假烫组和假烫给药组；伤后3d和5d,烫伤给药组大鼠胰腺组织3-NT蛋白表达水平显著低于烫伤组,显著高于假烫组和假烫给药组。Western Blot结果显示,假烫组和假烫给药组大鼠伤后各时相点胰腺组织Bcl-2相关X(Bax)蛋白表达水平均无明显升高或降低；伤后3d和5d,烫伤组大鼠胰腺组织Bax蛋白表达水平显著高于假烫组和假烫给药组；伤后3d和5d,烫伤给药组大鼠胰腺组织Bax蛋白表达水平低于烫伤组,显著高于假烫组和假烫给药组。Western Blot结果显示,假烫组和假烫给药组大鼠伤后各时相点胰腺组织Cleaved caspase-3蛋白表达水平比值均无明显升高或降低；烫伤组大鼠伤后各时相点胰腺组织Cleaved caspase-3蛋白表达水平显著高于假烫组和假烫给药组；烫伤给药组大鼠伤后各时相点胰腺组织Cleaved caspase-3蛋白表达水平低于烫伤组,高于假烫组和假烫给药组。结论：皮下注射Exendin-4可抑制胰腺脂质和蛋白质过氧化损伤,抑制胰腺过度炎症和凋亡级联反应,改善胰腺损伤程度,增加胰岛p细胞数量,促进严重烫伤大鼠伤后胰岛素分泌,降低空腹血糖浓度,但不会导致低血糖。
[Abstract]:Objective: it is easy to produce glucose metabolism disorder characterized by hyperglycemia after burn. The study shows that.Exendin-4 is a kind of GLP-1 receptor agonist, which is closely related to pancreatic injury after burn, and has high glucose dependent insulin secretion and does not lead to hypoglycemia. Exendin-4 can inhibit oxidative stress, inflammation and apoptosis, but the mechanism of Exendin-4 protection of pancreatic injury after severe burns is still lacking. Therefore, this study intends to explore the effect and mechanism of Exendin-4 on early pancreatic injury in severely scalded rats. Methods: 96 adult healthy Wistar rats were randomly divided into a sham perm group, an ironing group, and a perm group. The injured group and scald group were treated with 24 rats in each group. The rats in the scald group and the scald group were immersed in 94.C hot water for 12 seconds and the abdomen was 6 seconds, and the 50%TBSA III degree scald model was prepared. The rest treatment group and the fake ironing group were treated with warm water at 37 C, the rest treatment was the same. Exendin-4 (4ug/kg) was injected subcutaneously after the injury to the scald group and the sham perm group. After injury, each group was injured after injury. The same dosage of Sterile Water for Injection was given at 8:00 and 20:00 respectively. The rats in the other groups were given the same dose of Sterile Water for Injection in the same way. After injury, 1D, 3D and 5D were used to detect the concentration of fasting blood glucose in each group; the concentration of serum insulin was detected by radioimmunoassay; the moisture content of the pancreas was calculated by the dry wet mass method; HE staining was used to observe the pancreas shape. The content of malondialdehyde (MDA) in pancreatic tissue was detected by thiobarbituric acid; the expression of pancreatic inducible nitric oxide synthase (iNOS) was analyzed by immunohistochemistry; 3- nitro nitroso (3-NT), B cell lymphoma, -2 phase X protein (Bax) protein and activated partial cysteine aspartic acid were activated by immunoblotting The expression level of protease 3 (Cleaved caspase-3). Results: there was no significant increase or decrease in the concentration of fasting blood glucose at each time point in the rats of sham and sham ironing group. The concentration of fasting blood glucose in 1D, 3D and 5D after injury in the scald group was significantly higher than that in the sham group and the false ironing group; the concentration of 1D and 3D after injury in the scald group was significantly higher than that of the rats. The concentration of 1D's fasting blood glucose in the scald group was significantly higher than that of the sham group and the fake ironing group. The serum insulin concentration in the fasting serum at each time point in the sham group and the fake ironing group was not significantly elevated or decreased, and the concentration of the serum isshap in the fasting serum at each time point in the scald group was significantly higher than that of the sham group and the false scald group. In the scald group, the concentration of serum insulin in the fasting serum was significantly higher than that of the scald group. The water content of the pancreatic tissue in the rats of the sham group and the fake ironing group was not significantly increased or decreased, and the water content of the 1D pancreatic tissue in the scald group and the scald group was significantly higher than that of the sham group and the false scald group. Compared with the scald group, the water content in the pancreas tissue of the rats in the scald group was not significantly increased or decreased by the.HE staining results. The islet morphologic rules of the rats after the injury were found in the sham group and the false ironing group. The number of the beta cells was rich, the distribution was uniform, the cytoplasm was dense, and the vacuolated changes were found, and the rats in the scald group were 1D after injury. The number of the islet vacuoles and the number of P cells decreased, and the number of P cells decreased significantly in the 3D islets after injury. The number of 5D islet vacuoles was lighter than 3D after injury, and the number of beta cells was more than that of 3D after injury. The islet vacuoles in the scald group were all lighter than those in the scald group after injury. The content of malondialdehyde (MDA) in the pancreatic tissue of the rats of the sham group and the fake ironing group did not increase or decrease, and the content of the malondialdehyde (MDA) in the pancreatic tissue of the scald group was significantly higher than that of the false ironing group and the false ironing group. The content of the malondialdehyde (MDA) in the pancreas tissue of the rats in the scald group after injury was significantly higher than that of the rats in the scald group. Compared with the scald group and the scald group, the content of 5D pancreatic tissue malondialdehyde (MDA) in the scald group was lower than that of the scald group. The immunohistochemical results showed that the expression level of the islet induced nitric oxide synthase (iNOS) in the rats of the sham and sham group was not significantly increased or decreased after the injury. The expression level of islet inducible nitric oxide synthase (iNOS) in each phase point of rats after injury was higher than that in the sham group and the false ironing group, and the expression level of islet induced nitric oxide synthase (iNOS) in the rats after injury was lower than that in the scald group. The results of.Western Blot in the sham group and the sham ironing group showed that the sham group and the false ironing group were false and false. The level of the expression level of 3- nitrotyrosine (3-NT) protein in the pancreatic tissue of the rats after injury was not significantly increased or decreased, and the expression level of 3-NT protein in the pancreas tissue of the rats after injury was significantly higher than that of the sham group and the false ironing group in 3D and 5D after injury. The level of 3-NT protein expression in the pancreas tissue of the rats after injury was 3D and 5D. Significantly lower than the scald group, significantly higher than the false ironing group and the false ironing group.Western Blot results showed that the Bcl-2 related X (Bax) protein expression level in the pancreatic tissue of the rats of the sham group and the false ironing group did not increase or decrease, and the expression level of Bax protein in the pancreas tissue of the rats after injury 3D and 5D, and in the scald group was significantly higher than that of the sham group The expression level of Bax protein in pancreas tissue of rats with 3D and 5D after injury was lower than that of scald group, which was significantly higher than that of false ironing group and false ironing group.Western Blot. The ratio of Cleaved caspase-3 protein expression level in each phase point of the rats of sham perm group and false ironing group had no significant increase or decrease. In the scald group, the expression level of Cleaved caspase-3 protein in the pancreatic tissue of the rats after injury was significantly higher than that of the sham group and the false ironing group. The expression level of Cleaved caspase-3 protein in the pancreatic tissue of the scalded rats after injury was lower than that in the scald group, which was higher than that of the sham group and the false ironing group. Conclusion: the subcutaneous injection of Exendin-4 can be used as a result. Inhibition of pancreatic lipid and protein peroxidation damage, inhibition of pancreatic excessive inflammation and apoptosis cascade reaction, improve the degree of pancreatic injury, increase the number of islet P cells, promote insulin secretion in severely scalded rats, reduce the concentration of fasting blood glucose, but do not lead to hypoglycemia.

【学位授予单位】：中国人民解放军医学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R644

【共引文献】