【摘要】：目的：1.結(jié)扎大鼠冠狀動(dòng)脈左前降支(LAD)建立心肌梗死模型,觀測(cè)大鼠心肌梗死發(fā)生后心電圖ST段的演變過(guò)程,以探尋適當(dāng)?shù)腟T段檢測(cè)時(shí)間及導(dǎo)聯(lián)；2.探討甘蔗葉多糖的心肌保護(hù)作用及其機(jī)制,為甘蔗葉多糖的開(kāi)發(fā)利用提供依據(jù)。 方法：健康SD大鼠70只,雄性,體重230-250g,隨機(jī)分為甘蔗葉多糖組(多糖組)及模型對(duì)照組(對(duì)照組)。術(shù)前24h及術(shù)前30min,多糖組及對(duì)照組分別進(jìn)行灌胃處理,多糖組灌入濃度為4mg/ml甘蔗葉多糖溶液,劑量為lml/100g大鼠體重,模型組灌入等量生理鹽水,采用結(jié)扎大鼠LAD的方法建立急性心肌梗死模型,記錄開(kāi)胸前及術(shù)后1h內(nèi)每間隔5min的肢、胸導(dǎo)聯(lián)心電圖,測(cè)量心電圖各導(dǎo)聯(lián)各時(shí)刻ST段的偏移幅度。于術(shù)后第24h、48h、72h、96h繼續(xù)灌胃處理,濃度及劑量不變。末次灌胃30min后經(jīng)頸動(dòng)脈取血測(cè)量血清肌鈣蛋白含量(cTnI),并注射氯化鉀處死大鼠后,開(kāi)胸取出大鼠心臟,切除結(jié)扎線以上組織,放入10%甲醛溶液固定、包埋、切片。采用免疫組化法檢測(cè)血管內(nèi)皮生長(zhǎng)因子(VEGF)、CD34的表達(dá),應(yīng)用Image Pro-Plus6.0圖像分析系統(tǒng)對(duì)免疫組化圖像進(jìn)行分析。 結(jié)果：1.對(duì)照組心電圖演變過(guò)程：對(duì)照組42只大鼠術(shù)后有26只存活至實(shí)驗(yàn)終點(diǎn),經(jīng)病理HE染色證實(shí)20只出現(xiàn)心肌梗死。對(duì)照組在結(jié)扎LAD后1h內(nèi),與術(shù)前比較,Ⅰ、Ⅱ aVL、V2、V5導(dǎo)聯(lián)在各時(shí)刻ST段均抬高(P0.000),aVF、V1導(dǎo)聯(lián)術(shù)后各時(shí)刻心電圖無(wú)明顯變化,胸導(dǎo)聯(lián)ST段抬高較肢導(dǎo)聯(lián)明顯。自術(shù)后15min起,Ⅰ導(dǎo)聯(lián)的抬高值大于aVL導(dǎo)聯(lián)(P0.05)；術(shù)后25min內(nèi),Ⅰ導(dǎo)聯(lián)的抬高值大于Ⅱ?qū)?lián),之后無(wú)明顯差異；Ⅱ與aVL導(dǎo)聯(lián)無(wú)明顯差異,V2、V5導(dǎo)聯(lián)無(wú)明顯差異；術(shù)后1h內(nèi),ⅠI、aVL導(dǎo)聯(lián)分別自術(shù)后50mmin、35min起ST段的偏移幅度均低于術(shù)后10min (P0.05),而在Ⅱ、V2、V5導(dǎo)聯(lián)各觀測(cè)時(shí)點(diǎn)間的ST段偏移值差異無(wú)統(tǒng)計(jì)學(xué)意義。2.組間心電圖比較：術(shù)后1h內(nèi),多糖組各導(dǎo)聯(lián)ST段抬高值總體上小于模型組(P0.05)；兩組間每個(gè)時(shí)點(diǎn)比較,V2導(dǎo)聯(lián)的各時(shí)刻兩組間ST段偏移幅度均無(wú)差異,其他導(dǎo)聯(lián)特別是肢導(dǎo)聯(lián),在某些時(shí)刻多糖組ST段抬高值低于模型對(duì)照組。3.血清cTnI含量：多糖組與對(duì)照組cTnI含量均升高,但與模型對(duì)照組比較,多糖組血清中cTnI較低(P0.05)。4.免疫組化染色：光鏡下見(jiàn)VEGF蛋白在梗死區(qū)周圍心肌細(xì)胞胞質(zhì)內(nèi)被染成棕黃色顆粒狀,陽(yáng)性反應(yīng)強(qiáng)度用平均積分光密度(MIOD)表示,多糖組VEGF的平均光密度大于對(duì)照組(P0.05),即VEGF蛋白的含量高。采用CD34標(biāo)記血管內(nèi)皮細(xì)胞,光鏡下可見(jiàn)內(nèi)皮細(xì)胞胞漿著色為棕黃色,分布于梗死灶周圍的心肌細(xì)胞細(xì)胞之間,對(duì)CD34標(biāo)記的微血管進(jìn)行微血管計(jì)數(shù)(MVC),與對(duì)照組比較,多糖組MVC增多(P0.05)。 結(jié)論：1.結(jié)扎大鼠LAD后1h內(nèi),ST段的演變表現(xiàn)在Ⅰ、aVL導(dǎo)聯(lián)；采用心電圖肢導(dǎo)聯(lián)判斷大鼠是否心梗死時(shí),應(yīng)在術(shù)后早期觀測(cè)ST段的變；2.甘蔗葉多糖能改善心肌梗死大鼠心電圖表現(xiàn)；3.甘蔗葉多糖可降低心肌梗死大鼠血清中cTnI含量,對(duì)心肌細(xì)胞有一定保護(hù)作用；4.甘蔗葉多糖能促進(jìn)VEGF的表達(dá)及微血管的生成,促進(jìn)側(cè)枝循環(huán)的建立,對(duì)大鼠急性心肌梗死具有一定的保護(hù)作用。
[Abstract]:Objective:1. The model of myocardial infarction was established by ligation of the left anterior descending branch (LAD) of the coronary artery, and the evolution of the ST segment after myocardial infarction in rats was observed to find the appropriate ST segment detection time and lead;2. The function and mechanism of the myocardial protection of the sugarcane leaf polysaccharide were discussed, and the basis for the development and utilization of the sugarcane leaf polysaccharide was provided. Methods:70 male and 230-250g of healthy SD rats were randomly divided into two groups (group of polysaccharides) and control group (control group). The group was treated by intragastric administration for 24 h before and 30 min before operation, and the polysaccharide group and the control group were given intragastric administration respectively. The concentration of the polysaccharide group was 4 mg/ ml of the sugarcane leaf polysaccharide solution, the dosage was lml/100 g of the rat's body weight, the model group was injected with the same amount of normal saline, and the acute myocardial infarction was established by the method of ligation of the LAD in the rat. Model, record the limb of each interval of 5 minutes and the electrocardiogram of the chest lead, and measure the deviation of ST segment at each time of each lead of the electrocardiogram. Magnitude: Gavage, concentration and dosage were continued at 24 h,48 h,72 h, and 96 h after operation. the serum cardiac troponin content (cTnI) was measured by carotid blood sampling after 30 minutes of the last administration, and after the rats were killed by potassium chloride, the heart of the rat was taken out of the rat after injection of potassium chloride, the tissues above the ligation line were cut off, and the tissue was fixed and embedded in a 10% formaldehyde solution, The expression of vascular endothelial growth factor (VEGF) and CD34 was detected by immunohistochemical method, and the image was analyzed by Image Pro-Plus6.0 image analysis system. Analysis. Results:1. The evolution of the electrocardiogram in the control group:26 of the 42 rats in the control group survived to the end of the experiment. In the control group, the ST segment of the first, the second aVL, the V2 and the V5 leads were elevated at all time (P0.05), and the ST segment of the chest lead was higher than that of the control group after the ligation of the LAD for 1 hour. The elevation of the I-lead was higher than that of the aVL lead (P0.05). The elevation of the I-lead was greater than that of the II-lead in 25 minutes after the operation. There was no significant difference between the II and the aVL lead, and there was no significant difference between the two groups. The deviation of ST segment at 0 mmin and 35 min was lower than that of 10 min after operation (P0.05). 2. The ST-segment elevation of each lead in the group was less than that of the model group (P0.05). Don't be a limb lead. In some time, the ST segment elevation value of the polysaccharide group is lower than the model. In the control group, the content of cTnI in the serum of the group of the polysaccharide and the control group increased, but the cTnI in the serum of the polysaccharide group was lower than that of the control group (P0. (05).4. Immunohistochemistry staining: The expression of VEGF protein in the cytoplasm of the myocardial cells around the infarction area was stained with brown yellow particles under the light microscope, and the average integral optical density (MIOD) of the positive reaction intensity was higher than that of the control group (P0.05), that is, the VEGF egg. The content of white was high. CD34 was used to mark the vascular endothelial cells, and the cytoplasm of the endothelial cells was stained with brown-yellow cells under the light microscope. The microvessel count (MVC) of the CD34-labeled microvessel was compared with the control group, and the MVC of the group was increased (P 0.05) Conclusion:1. The evolution of ST segment in 1 h after the ligation of LAD in rats is shown in the 鈪，

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