【摘要】：目的：1.結扎大鼠冠狀動脈左前降支(LAD)建立心肌梗死模型,觀測大鼠心肌梗死發(fā)生后心電圖ST段的演變過程,以探尋適當?shù)腟T段檢測時間及導聯(lián)；2.探討甘蔗葉多糖的心肌保護作用及其機制,為甘蔗葉多糖的開發(fā)利用提供依據(jù)。 方法：健康SD大鼠70只,雄性,體重230-250g,隨機分為甘蔗葉多糖組(多糖組)及模型對照組(對照組)。術前24h及術前30min,多糖組及對照組分別進行灌胃處理,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,采用結扎大鼠LAD的方法建立急性心肌梗死模型,記錄開胸前及術后1h內(nèi)每間隔5min的肢、胸導聯(lián)心電圖,測量心電圖各導聯(lián)各時刻ST段的偏移幅度。于術后第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)頸動脈取血測量血清肌鈣蛋白含量(cTnI),并注射氯化鉀處死大鼠后,開胸取出大鼠心臟,切除結扎線以上組織,放入10%甲醛溶液固定、包埋、切片。采用免疫組化法檢測血管內(nèi)皮生長因子(VEGF)、CD34的表達,應用Image Pro-Plus6.0圖像分析系統(tǒng)對免疫組化圖像進行分析。 結果：1.對照組心電圖演變過程：對照組42只大鼠術后有26只存活至實驗終點,經(jīng)病理HE染色證實20只出現(xiàn)心肌梗死。對照組在結扎LAD后1h內(nèi),與術前比較,Ⅰ、Ⅱ aVL、V2、V5導聯(lián)在各時刻ST段均抬高(P0.000),aVF、V1導聯(lián)術后各時刻心電圖無明顯變化,胸導聯(lián)ST段抬高較肢導聯(lián)明顯。自術后15min起,Ⅰ導聯(lián)的抬高值大于aVL導聯(lián)(P0.05)；術后25min內(nèi),Ⅰ導聯(lián)的抬高值大于Ⅱ?qū)?lián),之后無明顯差異；Ⅱ與aVL導聯(lián)無明顯差異,V2、V5導聯(lián)無明顯差異；術后1h內(nèi),ⅠI、aVL導聯(lián)分別自術后50mmin、35min起ST段的偏移幅度均低于術后10min (P0.05),而在Ⅱ、V2、V5導聯(lián)各觀測時點間的ST段偏移值差異無統(tǒng)計學意義。2.組間心電圖比較：術后1h內(nèi),多糖組各導聯(lián)ST段抬高值總體上小于模型組(P0.05)；兩組間每個時點比較,V2導聯(lián)的各時刻兩組間ST段偏移幅度均無差異,其他導聯(lián)特別是肢導聯(lián),在某些時刻多糖組ST段抬高值低于模型對照組。3.血清cTnI含量：多糖組與對照組cTnI含量均升高,但與模型對照組比較,多糖組血清中cTnI較低(P0.05)。4.免疫組化染色：光鏡下見VEGF蛋白在梗死區(qū)周圍心肌細胞胞質(zhì)內(nèi)被染成棕黃色顆粒狀,陽性反應強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照組(P0.05),即VEGF蛋白的含量高。采用CD34標記血管內(nèi)皮細胞,光鏡下可見內(nèi)皮細胞胞漿著色為棕黃色,分布于梗死灶周圍的心肌細胞細胞之間,對CD34標記的微血管進行微血管計數(shù)(MVC),與對照組比較,多糖組MVC增多(P0.05)。 結論：1.結扎大鼠LAD后1h內(nèi),ST段的演變表現(xiàn)在Ⅰ、aVL導聯(lián)；采用心電圖肢導聯(lián)判斷大鼠是否心梗死時,應在術后早期觀測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,對心肌細胞有一定保護作用；4.甘蔗葉多糖能促進VEGF的表達及微血管的生成,促進側(cè)枝循環(huán)的建立,對大鼠急性心肌梗死具有一定的保護作用。
[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，

本文編號：2481153