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Objective To observe the effect of aerobics exercise on myocardial fibrosis after acute myocardial infarction (AMI) in rat.Methods Twenty-four AMI Sprague Dawley (SD) rats were randomly assigned to sham-operated group (Sham),AMI group and aerobics exercise treatment group (ET).Except Sham,other groups of rats were underwent anterior wall myocardial infarction.After ten weeks,the myocardial mRNA level of connective tissue growth factor (CTGF),collagen Ⅰ (COL1 a1),collagen Ⅲ (COL3a1) detected by real time-quantitative polymerase chain reaction (PCR) analysis and myocardial collagen volume fraction (CVF) was determined on Masson stained sections.Results Campared to Sham-operated group,AMI group the level of CTGF,COL1a1,COL3a1,and CVF were increased (P ＜0.05,P ＜ 0.01).Campared to AMI and ET groups,the levels of CTGF,COL1a1,COL3a1,and CVF were decreased (P ＜ 0.05,P ＜ 0.01).Conclusions Aerobics exercise can reduced the myocardial fibrosis after AMI in rat.
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<p><b>OBJECTIVE</b>To evaluate the feasibility of detecting macrophage content on atherosclerotic plaques by optical coherence tomography (OCT) technique.</p><p><b>METHODS</b>Thirty New Zealand white rabbits were equally divided into 3 groups at random: Control group (fed normal rabbit chow, n = 10); lipid diet group (fed regular chow supplemented with cholesterol, n = 10) and balloon injury+ lipid diet group (balloon catheter injury of the common carotid artery after 2 weeks lipid diet, n = 10). After 12 weeks, all rabbits underwent pharmacological triggering with Chinese Russell's viper venom (CRVV, 15 mg/kg, i.p.) and histamine (0.02 mg/kg, i.v.). Common carotid arteries were detected with OCT and the Movat pentachrome stain respectively. OCT and histological examination results were compared and the correlation was analyzed.</p><p><b>RESULTS</b>The intra thickness measured by Movat pentachrome stain and by the OCT was (15.2 ± 0.9) µm and (20.2 ± 7.6) µm, the medial thickness was (434.2 ± 86.5) µm and (453.8 ± 87.2) µm, the plaque thickness was (330.2 ± 87.1) µm and (392.2 ± 134.5) µm, the fibrous cap thickness was (58.3 ± 5.6) µm and (61.2 ± 4.9) µm, respectively (all P > 0.05). The normalized standard deviation of the OCT signal (NSD) was compared with immunohistochemical detection. The OCT signal within the cap is relatively homogeneous for low macrophage density in high lipid diet group. For the raw OCT data, a correlation of r = 0.846 (P < 0.01) was found between OCT NSD and a CD68 area<10%, whereas for the base 10 logarithm OCT data, a correlation of r = 0.646 (P < 0.05) was found between OCT NSD and a CD68 area<10%. In balloon injury + high lipid diet group, the OCT signal within the cap was relatively heterogeneous for high macrophage content. For the raw OCT data, a correlation of r = 0.906 (P < 0.01) was found between OCT NSD and a CD68 area >10%, whereas for the base 10 logarithm OCT data, a correlation of r = 0.593 (P < 0.05) was found between OCT NSD and a CD68 area >10%. For the raw OCT signal NSD, a range of NSDs (7.12% to 7.35%) demonstrated 100% sensitivity and specificity (Kappa value 1.0) for differentiating caps containing >10% CD68 staining. For the base 10 logarithm OCT signal, NSD values ranging from 7.81% to 7.92% provided 70% sensitivity and 75% specificity (value 0.44) for identifying caps containing >10% CD68 staining.</p><p><b>CONCLUSIONS</b>OCT is an effective tool to determine macrophage content in this model. OCT imaging can clearly visualize different types of atherosclerotic plaques and provide detailed information on plaque characteristics.</p>
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Animals , Rabbits , Carotid Artery, Common , Cholesterol , Fibrosis , Macrophages , Plaque, Atherosclerotic , Sensitivity and Specificity , Tomography, Optical CoherenceABSTRACT
Objeetive To investigate protective effect of trimetazidine on myocardial ischemia/reperfusion injury (MIRI) in rats.Methods Forty Wistar rats were randomly divided into MIRI group (n =10 rats),trimetazidine high-dosage group (n =10 rats; 20 mg/kg),trimetazidine low-dosage group (n=10 rats; 10 mg/kg),and the normal control group (n =10 rats).After MIRI,hemodynamic changes were observed,the concentration of IL-6 and TNF-α was determined,and the cardiac muscle histology under the microscope was observed.Results Hemodynamic studies:Compared to the indices LVSP(198 ±35.5) mmHg,LVEDP (17 ±9.18) mmHg,+ dp/dt max (11050 ± 1517.4) mmHg/s,and-dp/dtmax (9175± 1900) mmHg/s] in the sham-operated group,the indices [LVSP (143 ± 24.5) mmHg,LVEDP (37.5 ±7.16)mmHg,+ dp/dtmax (7450 ± 1755.1) mmHg/s,and-dp/dtmax (6075 ± 1641) Hg/S] in the MIRI group,the indices [LVSP (154.5 ± 31.1) mmHg,LVEDP (31.3 ± 12.6) mmHg,± dp/dtmax (8527.7 ±2251.5) mmHg/s,and-dp/dtmax (6694 ± 2242.2) mmHg/s] in the trimetazidine low-dosage (10 mg/kg)group,the indices[LVSP (168.3 ± 17.6) mmHg,LVEDP (28 ± 10.05) mmHg,+ dp/dtmax (9213.6 ±1747) mmHg/s,and-dp/dtmax (7568 ± 1462.4) mmHg/s] in the trimetazidine high-dosage (20 mg/kg)group,left ventricular remodeling end diastolic pressure (LVEDP),left ventricular systolic pressure (LVSP),and left ventricular pressure maxial rate of rise and fall (± dp/dtmax) were significantly decreased.Compared to the MIRI group,LVSP and ± dp/dtmax in the trimetazidine high-dosage (20 mg/kg)group were significantly increased (P ＜ 0.01),and myocardial damage of MIRI group was more severe in microscope.Compared to the sham-operated group [IL-6 (2556.5 ± 662.9) ng/ml,and TNF-α (134 ± 73.7)ng/ml],the corresponding indices [IL-6 (3664.0 ± 995.7) ng/ml,and TNF-α (443 ± 22.1) ng/ml] in the MIRI group,[IL-6 (3692.8 1545.2) ng/ml,and TNF-α (295 ± 24.2) ng/ml] in the trimetazidiue low-dosage (10 mg/kg) group,and[IL-6(2654.8 ±681.7) ng/ml,and TNF-α(230 ±7.8) ng/ml]in the trimetazidine high-dosage (20 mg/kg) group,the levels of IL-6 and TNF-α were significantly increased.Compared to the MIRI group,the levels of IL-6 and TNF-α were significantly decreased in the trimetazidine high-dosage (20 mg/kg) group (P ＜ 0.01).Conclusions The high-dosage (20 mg/kg) of trimetazidine had a protective effect on myocardial ischemia-reperfusion injury.
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Objective To observe the effect of depressive disorder on ventricular remodeling and its mechanism in acute myocardial infarction (AMI) rats. Methods Forty-six AMI Wistar rats were randomly divided into sham-operation (n=10), AMI (n=12), depression (n=12), neurostan by open field test, and the detection of angiotensin Ⅱ (Ag Ⅱ ), aldosterone (ALD), malondialdehyde (MDA), superoxide dismutase (SOD) were performed, the pathological sections were observed under light and electron microscopes. Results Compared with sham-operation group, depression group had decreased values of squares crossing times, rearing times and grooming time, increased time of staying in the central square and defecation. Compared with depression group, AMI and neurostan treatment groups had increased values of squares crossing times, rearing times and grooming time,decreased time of staying in the central square and defecation (F=16. 9, 44.56, 71.79, 34.86,29. 18, P＜0.01). At the 4 week of test, the left and right ventricular relative weights (LVRW,RVRW) and thickness of interventricular septum were (1.63±0.15) mg/g, (0. 48±0. 10) mg/g and (1.75 ± 0. 38) mm in sham-operation group, the corresponding data were (2.06±0.21) mg/g,(0.62±0.10) mg/g and (2.25±0.30) mm in AMI group, (2.90±0.47) mg/g, (1.00±0.28) mg/gand (2.58±0.34) mm in depression group, (2.20±0.34) mg/g, (0.67±0.15) mg/g and (2. 25±0.23) mm in neurostan treatment group. Compared with sham-operation group, AMI, depression and neurostan groups had obviously increased values of LVRW, RVRW and thickness of interventricular septum. Compared with depression group, AMI and neurostan groups had decreased LVRW, RVRW and thickness of interventricular septum (F=6.31, 21.9, 115.7, 9.91, P＜0.05). And the depression also could aggravate edema and injury of ultrastructure in myocardial tissue. The values of AgⅡ , ALD, MDA and SOD were (1957.5±662.6) ng/L, (0.453±0.111) ng/L, (16. 00±3.03)nmol/L and (80.57 ± 7.00) U/ml in depression group, the corresponding data were (1143.8± 98.0)ng/L, (0.198±0.087) ng/L, (8.03 ± 0.44 ) nmol/L and (95.20 ± 4.87) U/ml in sham-operated group, (1407.5±255.8) ng/L, (0.295±0.027) ng/L, (11.18±4.30) nmol/L and (87.33±3.51)U/ml in AMI group, (1400.0±239.0) ng/L, (0.326±0.073) ng/L, (11.88±3.36) nmol/L and (89.13 ±0.17) U/ml in neurostan group. After 4 weeks, the values of Ag Ⅱ , ALD and MDA increased in depression group while the level of SOD reduced (F=6.58, 11.9, 11.39, 8. 82, P＜0.05). Conclusions Depressive disorder after AMI in rats can aggravate ventricular remodeling and lower the ability of antioxygen.