【摘要】：目的:Roux胃旁路(Roux-en-Y gastric bypass,RYGB)能夠持續(xù)減輕體重,同時(shí)可以長期、有效的控制血糖,然而Roux胃旁路術(shù)有嚴(yán)格的手術(shù)適應(yīng)癥,適用于肥胖的2型糖尿病(type 2 diabetes mellitus,T2DM)患者。十二指腸空腸旁路術(shù)(duodenal-jejunal bypass,DJB)作為Roux胃旁路術(shù)的改良術(shù)式,術(shù)后胃的解剖結(jié)構(gòu)沒有發(fā)生改變,而僅僅曠置了近端小腸,對非肥胖T2DM患者也取得了一定的治療效果。本研究主要探討DJB對T2DM大鼠的治療效果,以及術(shù)后胃腸道激素和腸道糖代謝的改變,在血糖穩(wěn)態(tài)改善中所起的作用,該研究將為手術(shù)方式的改良,以及在T2DM治療過程中大力推廣外科手術(shù)方式,提供堅(jiān)實(shí)的理論依據(jù)。方法:1.SPF級雄性SD大鼠55只,利用隨機(jī)數(shù)字表法,隨機(jī)取40只作為高脂組(high-fat diet group,HFD),剩于15只為對照組(Control group,CON)。本研究采用高脂飼料喂養(yǎng)SD大鼠4周,并進(jìn)行胰島素耐量檢測,以確定誘導(dǎo)出胰島素抵抗。隨后尾靜脈注射鏈脲佐菌素(streptozocin,STZ),以誘導(dǎo)高血糖。采用血糖儀檢測該T2DM大鼠模型空腹血糖和隨機(jī)血糖,并分別于0周,4周和注射STZ后1周,采用ELISA方法測定其血清葡萄糖依賴性促胰島素樣多肽(gastric inhibitory polypeptide,GIP)的含量以及胰高血糖素樣肽-1(glucagon-likepeptide1,GLP-1)水平。2.從造模成功的大鼠中,挑選血糖、體重較為均一的大鼠進(jìn)行實(shí)驗(yàn)。按照隨機(jī)數(shù)字法將其分為DJB組和假手術(shù)組(S-DJB),每組15只,于注射STZ后第2周進(jìn)行相應(yīng)手術(shù)。對照組繼續(xù)普通飼料喂養(yǎng),不進(jìn)行任何干預(yù)。分別比較3組大鼠手術(shù)前后血糖、口服糖耐量、胰島素耐量、體重和進(jìn)食量的變化,以明確DJB對糖尿病大鼠的治療效果。同時(shí)檢測手術(shù)前后胰高血糖素、GLP-1和GIP水平的改變,以探究DJB改善糖代謝,與胃腸道激素的關(guān)系。3.于術(shù)后8周處死大鼠,取各組大鼠小腸及腸腔內(nèi)容物,用生理鹽水洗凈腸腔,無菌紗布吸干水分后稱其重量并觀察大體形態(tài)。隨后取其血清檢測總膽固醇、甘油三酯和游離脂肪酸等血脂水平的變化;采用熒光定量PCR和Western Blotting等技術(shù),檢測術(shù)后Roux腸袢涉及糖代謝與脂代謝關(guān)鍵酶基因和蛋白水平的改變;采用定量PCR的方法,對小腸不同部位腸腔內(nèi)容物中雙歧桿菌、擬桿菌、普拉梭菌和乳酸桿菌數(shù)量進(jìn)行檢測。結(jié)果:1.STZ注射后3天,高脂組大鼠空腹血糖和隨機(jī)血糖均顯著高于對照組。造模過程中高脂組大鼠血清GIP水平逐漸升高,GLP-1水平逐漸降低,至注射STZ后1周與對照組相比有顯著差異。2.術(shù)后8周,與S-DJB組相比,DJB組空腹血糖、血脂、口服糖耐量及胰島素耐量均顯著降低。DJB組空腹及餐后GLP-1水平均顯著升高,餐后GIP水平顯著降低,與S-DJB組相比有統(tǒng)計(jì)學(xué)差異,此外DJB組餐后胰高血糖素分泌顯著降低,與自身空腹水平相比有統(tǒng)計(jì)學(xué)差異。3.術(shù)后8周,DJB組Roux腸袢重量約為S-DJB組3倍。DJB組大鼠小腸參與葡萄糖攝取和利用的關(guān)鍵酶m RNA及蛋白水平均顯著升高,與S-DJB組相比有統(tǒng)計(jì)學(xué)差異。涉及膽固醇生物合成與攝取的關(guān)鍵酶m RNA及蛋白水平也顯著升高。DJB術(shù)后隨著營養(yǎng)物質(zhì)的流動(dòng),小腸涉及葡萄糖和膽固醇攝取和利用的關(guān)鍵酶和因子的m RNA水平成梯度改變。升高最明顯的是Roux腸袢,膽胰腸袢則沒有發(fā)生顯著差異,公共腸袢近端m RNA水平也顯著升高,而遠(yuǎn)端變化不明顯。DJB組Roux腸袢和公共腸袢雙歧桿菌、擬桿菌、普拉梭菌的數(shù)量顯著高于S-DJB組,而膽胰腸袢則沒有發(fā)生顯著改變。結(jié)論:1.DJB能顯著改善T2DM大鼠糖代謝狀態(tài),其術(shù)后空腹血糖、口服糖耐量以及胰島素耐量均顯著改善,而體重和進(jìn)食量則沒有明顯改變。2.胃腸道激素的改變,在T2DM發(fā)生發(fā)展過程中起到重要作用。同時(shí)DJB術(shù)后胃腸道激素的改變,在血糖穩(wěn)態(tài)的調(diào)節(jié)中起到了重要的作用。3.DJB術(shù)后,Roux腸袢涉及糖代謝和膽固醇合成的關(guān)鍵酶基因和蛋白水平均顯著增加。Roux腸袢重組腸道糖脂代謝,以滿足術(shù)后腸道重塑對能量的需求,使得腸道成為術(shù)后機(jī)體葡萄糖處置的重要器官,對術(shù)后血糖的控制起到了重要作用。未消化的營養(yǎng)物質(zhì)經(jīng)過Roux腸袢,可能是觸發(fā)腸道重塑和葡萄糖代謝重排列的原因。
[Abstract]:OBJECTIVE: Roux-en-Y gastric bypass (RYGB) can sustain weight loss and control blood glucose for a long time. However, Roux gastric bypass has strict surgical indications and is suitable for obese patients with type 2 diabetes mellitus (T2DM). The improved method of oux gastric bypass has not changed the anatomical structure of the stomach after operation, but only the proximal small intestine has been emptied. This study mainly discussed the therapeutic effect of DJB on non-obese T2DM rats, and the changes of gastrointestinal hormones and intestinal glucose metabolism after operation. Methods: Fifty-five SPF male SD rats were randomly selected as high-fat diet group (HFD) and 15 as control group (CON). The SD rats were fed with high-fat diet for 4 weeks, and insulin tolerance was tested to determine insulin resistance. Then the rats were injected with streptozocin (STZ) into the tail vein to induce hyperglycemia. Methods The serum levels of glucose-dependent insulin-like polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were measured. The control group was fed with normal diet without any intervention. The changes of blood glucose, oral glucose tolerance, insulin tolerance, body weight and food intake were compared before and after operation in order to determine the therapeutic effect of DJB on diabetic rats. Glucagon, GLP-1 and GIP levels were changed to explore the relationship between DJB and gastrointestinal hormones. 3. Rats were sacrificed at 8 weeks after operation. The intestinal and intestinal contents of each group were washed with normal saline. The intestinal cavity was dried by sterile gauze and weighed and gross morphology was observed. Changes of serum lipids levels such as triesters and free fatty acids were detected by fluorescence quantitative PCR and Western Blotting. Changes of genes and protein levels of key enzymes involved in glycometabolism and lipid metabolism in Roux loops were detected after operation. Results: 1. Fasting blood glucose and random blood glucose were significantly higher in the hyperlipidemia group than in the control group at 3 days after STZ injection. The fasting and postprandial GLP-1 levels in DJB group were significantly higher than those in S-DJB group, and the postprandial GIP levels were significantly lower than those in S-DJB group. In addition, the postprandial glucagon secretion in DJB group was significantly lower than that in S-DJB group, and there was a statistically significant difference between DJB group and its own fasting level. The levels of M RNA and protein, the key enzymes involved in glucose uptake and utilization, were significantly higher in DJB group than in S-DJB group. The levels of M RNA of key enzymes and factors for cholesterol uptake and utilization were gradiently changed.The most obvious increase was in Roux intestinal loop,but no significant difference was found in biliopancreatic intestinal loop.The level of M RNA in proximal end of common intestinal loop was also significantly increased,but the distal end was not significantly changed.The number of bifidobacteria in Roux intestinal loop and common intestinal loop in DJB group was significant. Conclusion: 1. DJB can significantly improve the glucose metabolism in T2DM rats, and the fasting blood glucose, oral glucose tolerance and insulin tolerance are significantly improved, but the weight and food intake are not significantly changed. 2. The changes of gastrointestinal hormones play an important role in the development of T2DM. At the same time, the changes of gastrointestinal hormones after DJB play an important role in the regulation of blood glucose homeostasis. 3. After DJB, Roux intestinal loop involved in glucose metabolism and cholesterol synthesis of the key enzyme genes and protein levels were significantly increased. Roux intestinal loop reconstituted intestinal glycolipid metabolism to meet the energy requirements of intestinal remodeling after DJB, making the intestinal tract become Undigested nutrients pass through the Roux loop, which may trigger intestinal remodeling and rearrangement of glucose metabolism.
【學(xué)位授予單位】：天津醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：R587.1;R656.6

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相關(guān)期刊論文 前5條

1 張巨彪;蘇秀蘭;歐陽曉暉;;1型糖尿病大鼠模型的建立及觀察[J];醫(yī)學(xué)綜述;2013年02期

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本文編號：2235671