| ObjectIn order to explore the impact of aerobic exercise with different lengths on vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) secretion, bFGF-R’s mRNA expression level and angiogenesis of heart tissue on rat after myocardial infarction (MI).MethodsForty male 8-week-old SD rats were randomly divided into sham operation group (Sham), myocardial infarction (MI), MI plus exercise with 2 weeks (ME2), MI plus exercise with 8 weeks (ME8),10 rats/group. MI model was constructed by anterior descending coronary artery (LAD) ligation surgery. Exercise training of ME group had been began one week after MI. Exercise program:after one week of adaptive motion,10 m/min warm-up with 10 min per day, then at a high intensity 20 m/min sports with 8min, then at low intensity 15 m/min sports with 2 min. There were 4 cycles alternating with high and low intensity. The last 20 m/min sports 8min, 10 m/min 2 min at the end of the exercise. It was training once a day,5 d/w, trained a total of 8 w. Rat cardiac ventricles wall thickness, ejection fraction were detected by two-dimensional echocardiography. Angiogenesis of heart tissue were detected by scanning transmission electron microscope. Westernblot myocardial tissue expression levels of CD34 to measure; by ELISA method to detect rat plasma cardiac tissue VEGF, bFGF secretion levels, mRNA level by RT-PCR of FGF-R.Results(1) MI caused a weight loss on the mice’s hearts, while the weight loss of the heart get improved obviously after aerobic exercise. Eight-week’s aerobic exercise can increase heart weight/weight and ventriculus sinister/weight to some extent.(2) MI surgery could attenuate the ventricular wall and reduce ejection function (EF) obviously; aerobic exercise thicken the RVWT and enhance the eject function of the MI mice. Among them,the sum of the thickness in diastolic ventricle septa and in diastolic left posterior wall of ME8 group is higher than that of MI group obviously (P<0.05).(3) The results of electron microscopy observation shows that,M1 hurt vascular endothelial cells of cardiac muscle tissues, widen the gap and split the basilar membrane. Newborn micro vessel can be seen both in ME2 group and ME8 group. Westernblot result of CD34 shows that the CD34 expression level of ME2 group is much higher than that of MI group clearly (P≤0.05),prompt that the degree of angiogenesis is active.(4)The VEGF secretion level of plasma and myocardium elevated significantly after aerobic exercise,among them VEGF level of plasma of ME2 group elevated obvious than that of MI group (P≤0.05).The VEGF level of plasma of ME8 group elevated significantly comparing with that of MI group (P≤0.01),and is higher than that of ME2 group (P≤0.05); The VEGF secretion level of myocardium of ME2 group and ME8 group is obviously higher than that of MI group respectively. (P≤0.01)(5) Aerobic exercise increased the secretion level of bFGF of plasma and myocardium,and the bFGF level both in plasma and myocardium of ME2 group and ME8 group is increased more significant than that of MI group.(6)Aerobic exercise advanced the mRNA expression level which expresses FGFR apparent, After two-week’s and eight-week’s aerobic exercise,mRNA expression level of cardiac muscle tissue FGFR elevated significantly comparing with that of MI group.conclusions(1) aerobic exercise is good for improving of MI mice’s ventricular diastolic and systolic function. (2) aerobic exercise is helpful to the rebirth of myocardial tissue and blood vessels of MT mice. (3) Aerobic exercise could help to promote angiogenesis by raising the the VEGF、bFGF secretion and the mRNA level of bFGF-R... |
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