Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm （LVA） in rabbits. Methods Acute myocardial infarction （AMI） was induced in 35 rabbits via conc...Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm （LVA） in rabbits. Methods Acute myocardial infarction （AMI） was induced in 35 rabbits via concomitant ligation of the left anterior descending （LAD） coronary artery and the circumflex （Cx） branch at the middle portion. Development of AMI was co n-firmed by ST segment elevation and akinesis of the occluded area. Echocardiography, pathological evaluation, and agar i n-tra-chamber casting were utilized to validate the formation of LVA four weeks after the surgery. Left ventricular end systolic pressure （LVESP） and diastolic pressure （LVEDP） were measured before, immediately after and four weeks after ligation. D i-mensions of the ventricular chamber, thickness of the interventricular septum （IVS） and the left ventricular posterior wall （LVPW） left ventricular end diastolic volume （LVEDV） and systolic volume （LVESV）, and ejection fraction （EF） were recorded by echo-cardiography. Results Thirty one （88.6%） rabbits survived myocardial infarction and 26 of them developed aneurysm （83.9%）. The mean area of aneurysm was 33.4% ＆#177; 2.4% of the left ventricle. LVEF markedly decreased after LVA formation, whereas LVEDV, LVESV and the thickness of IVS as well as the dimension of ventricular chamber from apex to mitral valve annulus significantly increased. LVESP immediately dropped after ligation and recovered to a small extent after LVA formation. LVEDP progressively increased after ligation till LVA formation. Areas in the left ventricle （LV） that underwent fibrosis included the apex, anterior wall and lateral wall but not IVS. Agar intra-chamber cast showed that the bulging of LV wall was prominent in the area of aneurysm. Conclusions Ligation of LAD and Cx at the middle portion could induce develo pment of LVA at a mean area ratio of 33.4%＆#177;2.4%which involves the apex, anterior wall and lateral wall of the LV.展开更多
Objectives To observe the effect of basic fibroblast growth factor (bFGF) slow-release microcapsules on angiogenesis in infarcted myocardial regions. Methods.Myocardial infarction was induced in 24 New Zealand rabbits...Objectives To observe the effect of basic fibroblast growth factor (bFGF) slow-release microcapsules on angiogenesis in infarcted myocardial regions. Methods.Myocardial infarction was induced in 24 New Zealand rabbits by ligating the root of left anterior descending coronary artery.Group Ⅰ(n=8) served as control, group Ⅱ(n=8) as a blank microcapsule group, group Ⅲ(n=8, each microcapsule contains 1μg bFGF) as micrpcapsule group.In group Ⅱ and Ⅲ, 5 blank microcapsules or bFGF slow-release microcapsules were implanted into myocardium underneath the epicardium between the left anterior descending coronary artery and left circumflex artery.Infarct size was evaluated by infarcted weight/left ventricle weight ratio and angiogenesis was evaluated by immunohistochemical examinations 5 weeks later. [WT5”BX] Results.As compared with group Ⅰ and Ⅱ, rabbits treated with bFGF slow-release microcapsules showed higher microvessel counts (group Ⅰ3775±450, group Ⅱ3837±498,vs.group Ⅲ 13550±481,P<0001) and less infarcted weight /left ventricle weight (group Ⅰ168%±04%,group Ⅱ167%±05%,vs.group Ⅲ 70%±02%,P<0001). Conclusions.Subepicardial administration of bFGF slow-release microcapsule in the infarcted rabbit model results in effective angiogenesis and reduction in infarct size.展开更多
To investigate the dynamic changes of serum vascular endothelial growth factor(VEGF) levels in a rat model of acute myocardial infarction. Materials and methods.Eighty eight adult male Sprague Dawley rats weighing app...To investigate the dynamic changes of serum vascular endothelial growth factor(VEGF) levels in a rat model of acute myocardial infarction. Materials and methods.Eighty eight adult male Sprague Dawley rats weighing approximately 270 g were used in this study. Eighty rats were subjected to left coronary artery ligation, with 8 rats for each different duration of infarct. Eight sham operated animals in which the left coronary artery was surgically exposed without ligation were used as controls. Blood samples were drawn from the right atrium before (sham animals) and 1,3,6,12,24 h and 2,3,5,7,14 d after myocardial infarction. The concentrations of serum VEGF were measured by a sensitive enzyme linked immunosorbent assay with a rabbit polyclonal antibody specific for VEGF. Results. In the 8 control animals, the mean concentration of serum VEGF was 66.99±17.83 pg/ml. Six hours after myocardial infarction, the level of serum VEGF significantly increased to 125.68±28.07 pg/ml (P<0.01 vs. sham controls), and reached a peak (240.61±70.63 pg/ml. P<0.01 vs. sham animals) at 24 h after ligation and then decreased gradually over the remaining 2 weeks. However, the level remained significantly elevated for 14 d (107.64±30.13pg/ml, P<0.01 vs. sham controls). Conclusion. The present study shows that the levels of serum VEGF are markedly increased until 14 d in the rat model of acute myocardial infarction. The increased serum VEGF level may play an important role in the angiogenesis associated with myocardial infarction.展开更多
Objective To explore the feasibility and safety of gene transfer into porcine myocardium via the pericardial cavity by a homemade easy device. Methods Replication-deficient recombinant adenoviral vector carrying LacZ ...Objective To explore the feasibility and safety of gene transfer into porcine myocardium via the pericardial cavity by a homemade easy device. Methods Replication-deficient recombinant adenoviral vector carrying LacZ report gene (Ad-LacZ) was constructed by the calcium phosphate precipitation method. Twelve healthy Chinese mini-swine were randomly divided into experimental group (n=6) and control group (n=6). Acute myocardial infarction (AMI) model was established by balloon occlusion of the distal part of D1 branch of left anterior descending (LAD) artery, at the same time the intra-pericardial cavity injections were performed through the small incision of the abdominal wall below the xyphoid appendix using a homemade device. Then gene transfer was performed using a central venous catheter. The pericardium was pretreated with injection of a mixture of collagenase (1 200 U) and hyaluronidase (3 000 U) in both groups. Then 2.0×109 plaque formation unit (PFU) Ad-LacZ was injected into the pericardial cavity in experimental group, while 1 mL of normal saline was injected in the control group. The β-galactosidase activity detection and X-gal staining of the ischemic myocardium were performed on the 3rd, 7th, and 28th day after injection. Results The LAD artery was occluded completely and infarction and ischemia were detected by histological assessment. In experimental group, the X-gal staining positive cells and β-galactosidase activity quantification were detectable on the 3rd day after injection, increased markedly on the 7th day, and then declined on the 28th day. The transfer efficiencies indicated by the positive myocardial cells were 16.7%, 45.6%, 22.8% on the 3rd, 7th, 28th day, respectively. In control group, no positive cells and β-galactosidase activity were observed. Conclusion Adenovirus can be transferred into ischemic myocardium and express target gene in the AMI model for four weeks with the homemade easy device via pericardial cavity pretreated by collagenase and hyaluronidase.展开更多
文摘Objectives To establish a cost-effective and reproducible procedure for induction of chronic left ventricular aneurysm （LVA） in rabbits. Methods Acute myocardial infarction （AMI） was induced in 35 rabbits via concomitant ligation of the left anterior descending （LAD） coronary artery and the circumflex （Cx） branch at the middle portion. Development of AMI was co n-firmed by ST segment elevation and akinesis of the occluded area. Echocardiography, pathological evaluation, and agar i n-tra-chamber casting were utilized to validate the formation of LVA four weeks after the surgery. Left ventricular end systolic pressure （LVESP） and diastolic pressure （LVEDP） were measured before, immediately after and four weeks after ligation. D i-mensions of the ventricular chamber, thickness of the interventricular septum （IVS） and the left ventricular posterior wall （LVPW） left ventricular end diastolic volume （LVEDV） and systolic volume （LVESV）, and ejection fraction （EF） were recorded by echo-cardiography. Results Thirty one （88.6%） rabbits survived myocardial infarction and 26 of them developed aneurysm （83.9%）. The mean area of aneurysm was 33.4% ＆#177; 2.4% of the left ventricle. LVEF markedly decreased after LVA formation, whereas LVEDV, LVESV and the thickness of IVS as well as the dimension of ventricular chamber from apex to mitral valve annulus significantly increased. LVESP immediately dropped after ligation and recovered to a small extent after LVA formation. LVEDP progressively increased after ligation till LVA formation. Areas in the left ventricle （LV） that underwent fibrosis included the apex, anterior wall and lateral wall but not IVS. Agar intra-chamber cast showed that the bulging of LV wall was prominent in the area of aneurysm. Conclusions Ligation of LAD and Cx at the middle portion could induce develo pment of LVA at a mean area ratio of 33.4%＆#177;2.4%which involves the apex, anterior wall and lateral wall of the LV.
文摘Objectives To observe the effect of basic fibroblast growth factor (bFGF) slow-release microcapsules on angiogenesis in infarcted myocardial regions. Methods.Myocardial infarction was induced in 24 New Zealand rabbits by ligating the root of left anterior descending coronary artery.Group Ⅰ(n=8) served as control, group Ⅱ(n=8) as a blank microcapsule group, group Ⅲ(n=8, each microcapsule contains 1μg bFGF) as micrpcapsule group.In group Ⅱ and Ⅲ, 5 blank microcapsules or bFGF slow-release microcapsules were implanted into myocardium underneath the epicardium between the left anterior descending coronary artery and left circumflex artery.Infarct size was evaluated by infarcted weight/left ventricle weight ratio and angiogenesis was evaluated by immunohistochemical examinations 5 weeks later. [WT5”BX] Results.As compared with group Ⅰ and Ⅱ, rabbits treated with bFGF slow-release microcapsules showed higher microvessel counts (group Ⅰ3775±450, group Ⅱ3837±498,vs.group Ⅲ 13550±481,P<0001) and less infarcted weight /left ventricle weight (group Ⅰ168%±04%,group Ⅱ167%±05%,vs.group Ⅲ 70%±02%,P<0001). Conclusions.Subepicardial administration of bFGF slow-release microcapsule in the infarcted rabbit model results in effective angiogenesis and reduction in infarct size.
文摘To investigate the dynamic changes of serum vascular endothelial growth factor(VEGF) levels in a rat model of acute myocardial infarction. Materials and methods.Eighty eight adult male Sprague Dawley rats weighing approximately 270 g were used in this study. Eighty rats were subjected to left coronary artery ligation, with 8 rats for each different duration of infarct. Eight sham operated animals in which the left coronary artery was surgically exposed without ligation were used as controls. Blood samples were drawn from the right atrium before (sham animals) and 1,3,6,12,24 h and 2,3,5,7,14 d after myocardial infarction. The concentrations of serum VEGF were measured by a sensitive enzyme linked immunosorbent assay with a rabbit polyclonal antibody specific for VEGF. Results. In the 8 control animals, the mean concentration of serum VEGF was 66.99±17.83 pg/ml. Six hours after myocardial infarction, the level of serum VEGF significantly increased to 125.68±28.07 pg/ml (P<0.01 vs. sham controls), and reached a peak (240.61±70.63 pg/ml. P<0.01 vs. sham animals) at 24 h after ligation and then decreased gradually over the remaining 2 weeks. However, the level remained significantly elevated for 14 d (107.64±30.13pg/ml, P<0.01 vs. sham controls). Conclusion. The present study shows that the levels of serum VEGF are markedly increased until 14 d in the rat model of acute myocardial infarction. The increased serum VEGF level may play an important role in the angiogenesis associated with myocardial infarction.
基金Supported by the Foundation of Medical Science and Technology Innovation Talent Project in Henan province (2001115).
文摘Objective To explore the feasibility and safety of gene transfer into porcine myocardium via the pericardial cavity by a homemade easy device. Methods Replication-deficient recombinant adenoviral vector carrying LacZ report gene (Ad-LacZ) was constructed by the calcium phosphate precipitation method. Twelve healthy Chinese mini-swine were randomly divided into experimental group (n=6) and control group (n=6). Acute myocardial infarction (AMI) model was established by balloon occlusion of the distal part of D1 branch of left anterior descending (LAD) artery, at the same time the intra-pericardial cavity injections were performed through the small incision of the abdominal wall below the xyphoid appendix using a homemade device. Then gene transfer was performed using a central venous catheter. The pericardium was pretreated with injection of a mixture of collagenase (1 200 U) and hyaluronidase (3 000 U) in both groups. Then 2.0×109 plaque formation unit (PFU) Ad-LacZ was injected into the pericardial cavity in experimental group, while 1 mL of normal saline was injected in the control group. The β-galactosidase activity detection and X-gal staining of the ischemic myocardium were performed on the 3rd, 7th, and 28th day after injection. Results The LAD artery was occluded completely and infarction and ischemia were detected by histological assessment. In experimental group, the X-gal staining positive cells and β-galactosidase activity quantification were detectable on the 3rd day after injection, increased markedly on the 7th day, and then declined on the 28th day. The transfer efficiencies indicated by the positive myocardial cells were 16.7%, 45.6%, 22.8% on the 3rd, 7th, 28th day, respectively. In control group, no positive cells and β-galactosidase activity were observed. Conclusion Adenovirus can be transferred into ischemic myocardium and express target gene in the AMI model for four weeks with the homemade easy device via pericardial cavity pretreated by collagenase and hyaluronidase.
