| In recent years, with the improvement of living standards, the prevalence of myocardial ischemia in our country presents the rising trend year by year. Myocardial ischemia occurs before the age of 40 and the average is 6.49%, It seriously damage to the heart of old people. Coronary artery narrow or occlusion is the most important and common reason of myocardial ischemia. There is about 50% blood of left ventricular come from the left anterior descending coronary artery. Around left anterior descending branch, there are many collateral vessels and little blood flow through them. In normal circumstances, they less affect the blood supplies of left ventricle. But, when the coronary artery was narrow, clogging, low oxygen or inflammation, many kinds of angiogenesis factors promote ceaselessly. It promotes the collateral vessels increasing and enlargement, the blood supplies of ischemia area increased and ischemia symptoms decreased. Radix pseudostellariae is both food and Chinese medicine, it was used to treat cough, infection, fatigue resistance, stress resistance, resistance to oxygen, improve immune function, prolong life and protect cardiac muscle etc. The proposed of this topic is ligation the left anterior descending of coronary artery to establish myocardial infarction model in rats. The therapeutic effects of TZSW on model rats were investigated by ECG, size of the ischemia tissues of myocardial infarction area, index of heart weight/body weight(HW/BW), the VEGF and CD31 expression in infarction cardiac tissue.Purposes1 To establish myocardial ischemia model of SD rats by ligation the left anterior descending of coronary artery and observe the effect of TZSW on the model rats, and investigate the possible mechanism.2 To establish hypoxia EA.Hy926 cell model by Co Cl2, to observe the effect of TZSW on hypoxia endothelial cells proliferation, migration and the formation of blood vessels and investigate the possible mechanism.Methods1 The effect of TZSW on protecting myocardial ischemia in rats(1) Ligate the left anterior descending of coronary artery in SD rats to establish the model of myocardial ischemia.(2) The model rats were treated by TZSW(1g/kg, 2g/kg) or normal saline via intragastric administration respectively, once a day, for four weeks.(3) Rats were anesthetized with 10% chloral hydrate via abdominal injection, ECG was recorded. And some of the rats' heart were removed, weighted and preserved for using.The index of HW/BW was calculated. Some of the rats' heart were stained both Evans blue and TTC to observe their morphology.(4) The rats' myocardial ischemia cardiac tissues were stained by HE to observe the effect of TZSW on size of myocardial infarction area.2 The effect of TZSW on coronary collateral circulation of myocardial infarction rats TZSW(1g/kg, 2g/kg) were used to treat the myocardial infarction rats for four weeks. The rats were also anesthetized with 10% chloral hydrate via abdominal injection. The rats were sacrificed and the hearts of rats were moved. The pathology slices of rats' myocardial tissues were prepared. The formations of new blood vessels were observed. The VEGF and CD31 expression of ischemic cardiac tissues were investigated by immunohistochemical staining.3 The effect of TZSW on hypoxia EA.Hy926 cells' proliferation, migration and tubular formation(1) To establish hypoxia EA. Hy926 cells model by Co Cl2.(2) To observe the effect of TZSW on hypoxia EA.Hy926 cells' proliferation by MTT.(3) To observe the effect of TZSW on hypoxia EA.Hy926 cells' ability to migrate by cell detachment test.(4) To observe the effect of TZSW on hypoxia EA.Hy926 cells' migration ability by transwell chamber(5) To observe the effect of TZSW on hypoxia EA.Hy926 cells' angiogenesis by Tube Formation experiment.(6) To observe the effect of TZSW on expression of CD31 of hypoxia EA.Hy926 cells by Western-blotting(WB).Results1 Myocardial infarction SD rats 's hearts are protected by TZSW(1)TZSW(1g/kg, 2g/kg) significantly reduced the size of ischemia tissues area in myocardial infarction rats' hearts. The percentage of ischemia area in myocardial infarction rats' hearts in TZSW(1g/kg) group was 28.01±7.12, and TZSW(2g/kg) group was 17.74 ±5.96, and normal saline group was 34.88±5.13. It had a significant difference between the TZSW 2g/kg group and normal saline group(P<0.01). This indicated that TZSW could protect the myocardial tissue from ischemia, reduce myocardial tissue necrosis and reduce infarction size.(2) The myocardial infarction rats were treated with TZSW for four weeks: the ECG of sham operation group maintain normal, ST segment of normal; saline group elevated obviously and T wave inversion; ST segment of TZSW 1g/kg group elevated;meanwhile ST segment of ECG in TZSW 2g/kg group was almost normal. This indicated that TZSW 2g/kg can improve myocardial ischemia anoxic symptom.(3) The myocardial infarction rats were treated with TZSW for four weeks: the HW/BW ratios of TZSW groups decreased obviously. The HW/BW ratio of TZSW 1g/kg and2g/kg groups were 3.10±0.21 and 3.06±0.17 respectively. The HW/BW ratio of normal saline treatment group was 3.35±0.19. There was significant difference between normal saline group and TZSW treatment group(P<0.01). This indicated that TZSW had anti-hypertrophy effect in myocardial compensatory hypertrophy caused by myocardial infarction. HW/BW ratio of normal saline group was significantly increased when it was compared with sham operation group, which the HW/BW ratio was 2.93±0.13(P<0.01). It showed that heart failure and myocardial compensatory hypertrophy were developed after ligation the left anterior descending coronary artery of rats.2 The effect of TZSW on coronary collateral circulation of myocardial ischemia SD rats(1) Immunohistochemical staining showed that the expression of VEGF in normal saline group was increased when it was compared with sham operation group,meanwhile the expression of VEGF in ischemic cardiac tissue was significantly up-regulated by TZSW(1g/kg,2g/kg), This show that TZSW promotes VEGF expression in ischemic cardiac tissues in myocardial infarction rats.(2) Immunohistochemical staining showed that the expression of CD31 protein in normal saline group was increased when it was compared with sham operation group,while the expression of CD31 protein of TZSW(1g/kg, 2g/kg) groups significantly increased to compare with normal saline group, which show that TZSW promotes collateral circulation of myocardial infarction rats' hearts and ischemic myocardial angiogenesis.3 The effect of TZSW on proliferation, migration and the small tube forming of hypoxia EA.Hy926 cells induced by Co Cl2.(1) The optimum concentration and time course of hypoxia EA.Hy926 cell model induced by Co Cl2 was 0.35mmol/L in 3h.(2) TZSW 4-12 mg/ml can promote the hypoxic EA.Hy926 cell proliferation induced by Co Cl2 in a dose dependent relationship and timeliness. The optimum concentration and the time promote hypoxic EA.Hy926 cells proliferation induced by Co Cl2 was 6 mg/ml in 24 h.(3) It was found that TZSW 6mg/m L has no apparent inhibition to EA. Hy926 cell migration by scratch method.(4) It was found that TZSW 6mg/m L can enhance the hypoxia EA.hy926 cell migration by trasnswell chamber method.(5) It was found that TZSW 6mg/m L can promote the tube formation of endothelial cell and micro blood vessels formation by Tube Formation experiment.(6) TZSW 6mg/ml promotes the expression of CD31 protein of hypoxia EA.hy926 cells,which has significant difference to compare with the blank control group(P<0.01).Conclusions1 TZSW had anti-ischemia in myocardial ischemic rats. It could reduce the ischemic area in myocardial ischemic rats and protect the heart function. TZSW could inhibit cardiac hypertrophy induced by myocardial ischemia. The effect of TZSW against rats' myocardial ischemia by up-regulation of VEGF and CD31 protein expression, promotedthe micro vessel density and coronary collateral circulation.2 In vitro, TZSW could promote the proliferation, migration and tubule formation of hypoxia EA.hy926 cells induced by Co Cl2, which might be related to the up-regulation of CD31 protein expression in hypoxic EA.hy926 cells. |
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