心肌内控制释放碱性成纤维细胞生长因子血管再生机制的探讨

目的:评价心肌内控制释放碱性成纤维细胞生长因子(bFGF)对急性心肌梗死(AMI)犬局部相关血 管生长因子表达与细胞增殖水平的影响,探讨bFGF血管再生治疗的可能机制。方法:将12只成年健康杂种犬 结扎左前降支(LAD)制作AMI模型。动物随机分为两组:激光心肌血运重建(TMR)组于AMI30min后行透壁 心肌打孔;bFGF组则于AMI30min后行非透壁心肌打孔,并随后向孔道内注射含有bFGF的纤维蛋白胶(FG)。 术后第8周,采用免疫组织化学染色和计算机形态学分析评价缺血心肌局部血管内皮生长因子(VEGF)、转化生 长因子β1(TGF β1)和增殖细胞核抗原(PCNA)表达水平的变化。结果:免疫组织化学定量分析发现,bFGF组梗 死区心肌VEGF、TGF β1和PCNA染色的显色面积[(9.27±1.74),(9.82±0.99)与(32.11±5.78)μm3]均高于 TMR组[(5.65±0.99),(9.11±0.47)与(17.14±6.70)μm3](均P<0.05),bFGF组PCNA染色的平均吸收度 也高于TMR组(0.3696±0.0204与0.3043±0.0443,P<0.05)。结论:心肌内控制释放bFGF,能提高缺血心肌 局部相关血管生长因子(如VEGF、TGF β1等)的表达水平,增强细胞增殖,从而促进血管再生。     

心肌内注射bFGF对糖尿病合并急性心肌梗死大鼠左室功能、肌球蛋白重链基因表达的影响

目的观察心肌内注射碱性成纤维细胞生长因子（bFGF）对糖尿病合并急性心肌梗死（AMI）大鼠左室功能、肌球蛋白重链（α、β-MHC）、mRNA表达的影响。方法用GK大鼠和Wistar大鼠建立前壁AMI模型后,将GK大鼠随机分为模型组（n=12）和治疗组（n=13）,模型组于心肌内注射生理盐水3ml,治疗组于心肌内注射bFGF6mg＋生理盐水共3ml;Wistar大鼠为对照组,行心脏假手术后于心肌内注射生理盐水3ml。饲养至3周后行血流动力学、左室心肌α、β-MHCmRNA测定。结果模型组左室舒张末压（LVEDP）、pMHCmRNA明显高于对照组,α-MHCmRNA显著低于对照组。治疗组LVEDP、β-MHCmRNA明显低于模型组,α-MHC mRNA显著高于模型组。结论心肌内注射bFGF能提高DM合并心肌梗死大鼠左室功能,逆转心室重塑过程中心肌肌球蛋白重链基因表型改变,延缓心脏衰竭的发展。     

心肌内控制释放bFGF血管再生治疗对急性心肌梗死犬心室重构的影响

目的采用病理与超声心动图方法评价心肌内控制释放碱性成纤维细胞生长因子(bFGF)血管再生治疗对急性心肌梗死(AMI)犬心室重构的影响.     

激光心肌孔道内控制释放bFGF对急性心肌梗死犬心脏功能的影响

目的探讨在激光打孔的心肌孔道内埋植控制释放碱性成纤维细胞生长因子(bFGF)的纤维蛋白胶(FG)对急性心肌梗死(AMI)犬整体心脏收缩与舒张功能的影响.     

高压氧治疗对急性心肌梗死患者心肌代谢和心脏功能的保护作用

目的评价高压氧(HBO)治疗对急性心肌梗死(AMI)患者梗死面积和心功能的影响。方法 18例符合入选标准的患者根据其本人或家属意愿分为对照组(n=9,仅接受常规药物治疗)和观察组(常规药物治疗+HBO治疗)。患者于治疗前及治疗10、20d后用Wagner的QRS记分法预测梗死面积,用血流动力学参数监测心脏功能,并进行比较。结果①治疗前两组患者的QRS记分和血流动力学参数比较差异无统计学意义(P0.05);②治疗10d后,观察组的QRS记分明显低于对照组(P0.05),血流动力学参数CO、C、ISV、SI、LVSW、ILCW、IVI明显高于对照组(P0.05);③治疗20d后,两组上述血流动力学参数无显著差异(P0.05),但QRS记分观察组较对照组进一步下降(P0.01),而对照组与治疗前比较存在显著差异(P0.05)。结论 HBO有防止AMI面积延展、加速受损心肌细胞修复、改善心脏功能的作用。     

心肌内控制释放碱性成纤维细胞生长因子促进血管再生与侧支重构

目的评价心肌内控制释放碱性成纤维细胞生长因子(bFGF)血管再生治疗对急性心肌梗死犬血管再生与侧支重构的影响。方法18只成年健康杂种犬制作急性心肌梗死模型,随机分为单纯心肌梗死组、激光心肌血运重建(TMR)组和bFGF组,每组6只。术后第8周,采用第八因子免疫组织化学染色和计算机形态分析评价血管再生与侧支重构的变化。结果直接血管计数发现,bFGF组镜下总血管计数和直径≥50μm的较大微血管数均高于TMR组和单纯心肌梗死组(P<0.001)。bFGF组的第八因子相关抗原染色显色面积和平均吸光度均高于TMR组与单纯心肌梗死组(P<0.001);在TMR基础上在心肌内控制释放bFGF能使总血管数增加近30%,其中直径≥50μm的微血管数增加近60%。结论采用纤维蛋白胶在心肌内控制释放bFGF的血管再生治疗安全可行,能有效促进缺血心肌内的血管再生和侧支重构。     

细胞移植对心肌梗死后心脏功能的影响

心肌梗死所致的细胞丢失和瘢痕形成是影响心脏功能的主要因素 ,也是导致顽固心力衰竭 (心衰 )乃至死亡的病理基础。心肌梗死的治疗 ,包括药物治疗、介入治疗和手术治疗。他们能够改善心肌缺血和心衰的症状 ,使闭塞的血管再通 ,却不能够替代不可复生的坏死心肌。而心脏移植虽能取代受损心脏 ,但供体难以选择 ,费用高 ,临床很难推广。近年来 ,新兴的细胞生物工程技术实现了体外细胞的培养 ,并通过移植技术试图使移入的细胞在受损心肌组织中生存增殖 ,替代坏死心肌 ,改善心脏功能。对此 ,国外已做了大量的研究 ,国内也极为关注。一、细胞移植的…     

急性心肌梗死后血管内皮细胞生长因子及碱性成纤维细胞生长因子表达动态变化

目的　以急性心肌梗死大鼠为模型,观察血管内皮细胞生长因子(VEGF)和碱性成纤维细胞生长因子(bFGF)在心肌中的表达,探讨急性缺血缺氧刺激下VEGF和bFGF表达变化与新生血管形成的关系及意义。方法　建立Wistar大鼠急性心肌梗死模型,分为对照组和急性心肌梗死组( 3d ,7d ,1 4d ,2 8d ,4 2d ,56d)。免疫组化检测心肌细胞和内皮细胞中VEGF和bFGF的表达,Ⅷ因子相关抗原标记内皮细胞,检测新生毛细血管密度。结果　实验组心肌梗死后VEGF和bFGF产生量迅速增加,梗死区VEGF和bFGF的表达在梗死后第7天达高峰,2 8天开始下降,4 2天和56天时表达明显下降,新生毛细血管密度与两者产生量成正相关,与对照组比较差异有统计学意义。结论　在心肌梗死急性缺血期心肌细胞和内皮细胞能通过自身分泌VEGF和bFGF协同刺激血管内皮细胞增殖,促进血管形成,从而改善缺血心肌的血液供应。二者的表达在梗死后第7天达到最高峰,第2 8天时开始下降,为选择在表达消退期应用外源性VEGF和bFGF进行基因治疗提供了实验依据。     

心肌内注射碱性成纤维细胞生长因子基因对兔缺血心肌血管新生的促进作用

目的 :探讨心肌内注射碱性成纤维细胞生长因子基因 (b FGF基因 )治疗兔急性心肌梗死模型的效果。方法　碱裂解法大量制备质粒 ;采用开胸结扎兔冠状动脉左前降支 (L AD)法 ,建立兔急性前壁心肌梗死模型。模型制备成功后将动物分为治疗组 (n=19)和对照组 (n=18) ,并于心肌内分别注射 pc DNA3- b FGF10 0 μg和 pc DNA310 0 μg,饲养至 2 ,6 ,12周处死 ;免疫组化观察蛋白表达 ;行病理切片观察心肌梗死组织学变化和缺血心肌内血管新生的情况。结果　 (1)术前术后描记的心电图证实兔急性心肌梗死模型制作成功 ;(2 )免疫组化观察注射 pc DNA 3- b FGF处心肌组织在 6周内有 b FGF蛋白的表达 ;(3)病理切片行图像分析计算血管密度发现 ,治疗组毛细血管密度和小动脉密度显著高于对照组。结论　心肌内注射 b FGF基因能促进缺血心肌内血管新生 ,有可能成为一种新的冠心病治疗方法     

容量超负荷心肌肥大时局部心肌AngⅡ,bFGF的变化及ATI受体拮抗剂对其影响的实验研究

目的 :观察急性容量超负荷心肌肥大 （MH）早期局部心肌碱性成纤维细胞生长因子 （b FGF）及血管紧张素 （Ang ）的作用以及 Ang 1型受体 （AT1）拮抗剂 （Losartan,Los）的逆转 MH作用。方法 :选择 3 6只雄性 SD大鼠随机分为 3组 :腹腔动静脉造瘘容量超负荷组 （AVO组 ）、容量超负荷治疗组 （L OS组 ）及对照组 （CON组 ） ,每组 12只 ,对比检测术后第 10天和第 2 0天的收缩压 （SBP）、左室重量指数 （LVMI）、心肌羟脯氨酸 （HY）、b FGF,Ang 及血浆 Ang 含量。结果 :1ACF组 SBP和 L VMI第 10天和第 2 0天持续升高 （P<0 .0 5 ,vs CON组 ） ,给药后二者水平仍显著高于对照组 ,但较 ACF组明显下调 ;2 ACF组心肌 b FGF和 Ang 第 10和第 2 0天明显上升 （P<0 .0 5 ,vs CON组 ） ,AT1受体被阻断后第 10天心肌 b FGF显著升高 （P<0 .0 5 ,vs ACF组 ） ,第 2 0天无明显变化 （P>0 .0 5 ,vs ACF组 ） ,而心肌和血浆 Ang 较 ACF组明显增多 （P<0 .0 5 ） ;3心肌 b FGF,Ang 及 L VMI之间均呈显著正相关。结论 :心肌 b FGF可能和 Ang 共同参与急性容量超负荷 MH早期发生 ,其产生可能与心肌 Ang 有关 ,AT1受体拮抗剂早期具显著逆转 MH作用     

心肌注射碱性成纤维细胞生长因子促进犬侧支血管形成的实验研究

目的　评价在犬急性心肌梗死模型中 ,心肌内注射碱性成纤维细胞生长因子 (bFGF)对心肌局部血流量及侧支血管形成的影响。方法　 17条杂种犬 ,结扎第一、第二对角支和第一、第二钝缘支造成急性心肌梗死模型。冠状动脉结扎 2 0min后 ,治疗组 (n =9)在梗死边缘区心肌 5点注射2 0 0 μgbFGF ,对照组 (n =8)以相同的方法注射生理盐水 2 0 0 μl。在冠状动脉结扎之前、结扎即刻、结扎后 3h、7d及 2 8d使用非放射性彩色微粒子测量心肌局部血流量。试验终点观察侧支血管密度变化。结果　与对照组相比 ,治疗组心肌注射 2 0 0 μgbFGF后 ,梗死区心外膜心肌局部血流量明显增加 :冠状动脉结扎 3h治疗组心肌血流量为 (36 4 0± 2 0 4 ) % ,对照组为 (32 32± 3 0 7) % ,P <0 0 5 ;7d后治疗组为 (5 6 30± 3 4 9) % ,对照组为 (35 6 8± 1 6 2 ) % ,P <0 0 1;2 8d分别为 (70 6 2±3 17) % ,(46 2 0± 2 5 8) % ,P <0 0 1。与之相似 ,治疗组梗死边缘区心外膜心肌血流量也明显增加 :冠状动脉结扎 7d治疗组为 (6 8 0 6± 2 6 9) % ,对照组为 (5 3 94± 2 2 7) % ,P <0 0 1;2 8d治疗组为(79 74± 4 6 1) % ,对照组为 (6 1 84± 4 5 2 ) % ,P <0 0 1。与对照组相比 ,治疗组梗死区血管密度 :治疗组为 (7 2     

Effects of intramyocardial administration of slow-release basic fibroblast growth factor on angiogenesis and ventricular remodeling in a rat infarct model.

BACKGROUND: Basic fibroblast growth factor (bFGF) stimulates neoangiogenesis. Incorporation into biodegradable gelatin hydrogels provides the sustained release of bFGF. The effects of intramyocardial injections of slow-release bFGF on neoangiogenesis in a rat model of infarction were investigated. METHODS AND RESULTS: Myocardial infarction was induced in rats using coronary artery ligation. A total of 124 rats received an intramyocardial injection of 20 microg of bFGF, the same amount of bFGF incorporated into gelatin hydrogel (bFGF + gel), gelatin hydrogel (gel) or saline. Ventricular function was evaluated by echocardiography 2 or 4 weeks later. Morphometric and histological analyses were used to evaluate infarct size, vascular density and myocardial apoptosis. Capillary density in the infarct border zone was higher in the bFGF and bFGF + gel groups than in the saline and gel groups at 4 weeks (p<0.001). Arteriolar density was higher in the bFGF + gel group than in the other 3 groups (p<0.05). The bFGF and bFGF + gel groups contained fewer apoptotic cardiomyocytes in the border zone than the saline and gel groups (p<0.01). The bFGF+gel group had thicker (p<0.05) and less expanded infarcts (p<0.01) compared with the saline group at 4 weeks. CONCLUSIONS: Incorporation of bFGF in gelatin hydrogels enhanced the effects of bFGF on arteriogenesis, ventricular remodeling and cardiac function.     

肝细胞生长因子对犬急性心肌梗死后左心室重构的影响

目的探讨肝细胞生长因子(hepatocyte growth factor,HGF)对急性心肌梗死后左心室重构的影响。方法将12只杂种犬结扎左冠状动脉前降支,复制急性心肌梗死模型,随机分为2组:对照组和治疗组,每组6只。治疗组于梗死心肌周围注射pc-DNA3-HGF基因1 ml,对照组给予等量的生理盐水。分别于术后1、4、8周进行超声心动图检查,检测心功能、左心室重构指标。术后8周取心肌组织行HE染色及天狼猩红染色,图像分析系统测定Ⅰ、Ⅲ型胶原含量。结果术后4周时,治疗组左心室射血分数(LVEF)明显高于对照组(P<0.05)。8周时,LVEF明显升高,左心室舒张末容积较对照组降低(P<0.05)。对照组组内比较显示左心室后壁厚度显著降低(P=0.04)。HE染色可观察到治疗组梗死心肌周围毛细血管较对照组增多,而对照组瘢痕形成明显。天狼猩红染色显示治疗组Ⅲ型胶原含量高于对照组,Ⅰ/Ⅲ型胶原比例低于对照组(P<0.05)。结论HGF可能通过减少胶原的沉积及促进血管增生,减少心肌坏死及瘢痕形成,从而改善心功能及急性心肌梗死后的左心室重构。     

Elevated circulating levels of basic fibroblast growth factor and vascular endothelial growth factor in patients with acute myocardial infarction

Basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) have both shown strong angiogenetic effects in ischemic animal models and it has been reported that these growth factors were increased after acute myocardial ischemia. However, there have been few reports on the serum levels of bFGF and VEGF after acute myocardial infarction (AMI), in particular there has not been a comparative study of bFGF and VEGF in human subjects. The time course of circulating levels of bFGF and VEGF was examined in 36 patients with AMI who were within 24h of the onset of the AMI. The serum bFGF and VEGF levels of 50 age- and sex-matched healthy volunteers served as the baseline value. All the patients had undergone coronary angiography on the day of admission (Day 0), but prior to that the serum bFGF and VEGF levels were examined by enzyme-linked immunoassay. The serum bFGF and VEGF levels were also evaluated on Days 7, 14 and 28. Creatine kinase, myosin light chain I and troponin-T were measured subsequently and radionuclide examinations were performed during the early phase of AMI to determine the infarct size. The serum bFGF levels were significantly increased at Day 0 and were maintained until Days 7 and 14. Although serum VEGF levels at Day 0 were similar to the baseline values, they showed a remarkable increase by Days 7 and 14. A high serum level of bFGF was detected in the acute phase of AMI, and a later increase in VEGF was determined in the sub-acute phase, which suggest that these 2 growth factors play an important role at different time points of the reconstructing process of infarcted myocardial tissue.     

Reduction in myocardial infarct size by basic fibroblast growth factor following coronary occlusion in a canine model

In a canine model of permanent coronary occlusion it has been shown that basic fibroblast growth factor (bFGF) reduced infarct size and this was associated with an increase in myocardial capillary density a week after infarction. In a preliminary work from our own laboratory using a model of occlusion followed by prolonged reperfusion we observed a similar reduction in infarct size without evidence of myocardial neovascularization. The aim of the present investigation was to evaluate the effects of bFGF on infarct size and blood flow to the infarct zone in an acute experiment in which myocardial neovascularization would be excluded as a mechanism by the short duration of the study. Seventeen mongrel dogs were anesthetized and the heart was exposed through a left thoratocomy. The left anterior descending (LAD) coronary artery was isolated and occluded for 3 h. Fifteen min after LAD occlusion dogs received bFGF 20 μg of bFGF (n=6) or placebo (n=11) by intracoronary injection infused over 5 min. We measured heart rate, aortic pressure, regional coronary blood flow (CBF), regional shortening fraction (SF) at 1, 30 and 180 min of occlusion, then the LAD was reperfused for 5 min then the dogs were euthanized and infarct size was measured. Regional CBF was similar between the two groups of dogs throughout all the study. The SF was similar between the two groups prior the onset of ischemia and at the beginning of the ischemic period. After 180 min of ischemia SF was 2.7±4.1% for bFGF and −3.1±4.7 for placebo (P=0.049), and during reperfusion SF was 3.4±4.6% for bFGF and 0.4±1.0% for placebo treated dogs (P=0.023). The infarct size, normalized for the area at risk was 14.2±5.2% in bFGF group vs 25.8±8.2% in placebo group (P=0.015). In summary we have demonstrated that bFGF significantly limits myocardial necrosis after acute coronary occlusion, and that this occurred without an increase in regional myocardial perfusion and within a period of time too brief for angiogenesis to have occurred. By exclusion, it appears that the salutary effect of bFGF is likely to be mediated by a cellular mechanism. The mechanism or mechanisms responsible for myocardial salvage by bFGF may have significant potential to be exploited in the clinical arena as the basis for therapies to protect the acutely ischemic myocardium.     

bFGF促进缺血心肌血管生成和改善心肌功能的实验研究

目的利用生长因子通过诱导血管生成治疗缺血性心脏病,但生长因子的输入方式还存在一些争议。本研究旨在探讨心肌内注射碱性成纤维生长因子（bFGF）对急性心肌梗死（AM I）血管生成和心肌功能的作用。方法AM I犬24只,随机分成对照组（M I区注射生理盐水15 m l）和实验组（M I区注射50 mg bFGF与生理盐水的混合液15 m l）;每组观察4个不同的时间点（术后0、2、9、16 d）。各组动物分别在处死前应用敏感编码技术（sensitivity en-coded techn ique,SENSE）行磁共振电影成像（c ine m agnetic resonance im aging,c ine-MR I）;电镜直接观察新生血管生长情况;免疫组织化学方法检测各组微血管数量;以左心室射血分数（LVEF）评价心脏功能的改变。结果实验组LVEF自9 d明显增加[9 d:对照组（24±3）%、实验组（46±6）%;16 d:对照组（31±5）%、实验组（53±5）%];除0d外各个时间点的微血管数量实验组均比对照组明显增多[2 d:对照组（92±12）支/视野、实验组（147±12）支/视野;9 d:对照组（125±12）支/视野、实验组（183±14）支/视野;16 d:对照组（125±14）支/视野、实验组（224±20）支/视野]。结论心肌内注射bFGF具有促进M I区域毛细血管形成及改善左心室功能的作用。