孟亮
中国医学科学院阜外医院 动物实验中心
OBJECTIVE:Due to the weak ascending aorta, it is extremely challenging to establish an anterograde selective cerebral perfusion (ASCP) model in rabbits, especially when cardioplegic arrest is required. Herein, the aim of this study was to establish a rabbit ASCP model with cardiac arrest being easily performed and being similar to the clinical scenario.MATERIALS AND METHODS:Twenty-two adult New Zealand white rabbits were selected for ASCP model establishment and another 22 rabbits were utilized for blood donation. The cardiopulmonary bypass (CPB) circuit consisted of a roller pump, a membrane oxygenator, a heat-cooler system and a blood reservoir, which were connected by silicone tubing. The total priming volume of the circuit was 70 ml. Cannulations on the right and left subclavian arteries were used for arterial inflow and cardioplegia perfusion, respectively. Venous drainage was conducted through the right atrial appendage. ASCP was initiated by clamping the innominate artery; the flow rate was maintained 10 ml/kg/minute and sustained for 60 minutes. After 120 minutes of reperfusion, the rabbits were sacrificed. The mean arterial pressure, heart rate, electrocardiogram and urine output were monitored. Arterial blood samples were analyzed at the following time points: after anesthesia, immediately after CPB, after aorta cross-clamping and cardioplegia perfusion, 5 min after the re-opening of the aorta and at CPB termination.RESULTS:ASCP modeling was performed successfully on 18 rabbits and 4 rabbits unsuccessfully. Vital signs and blood gas indictors changed in an acceptable range throughout the experiments. One rabbit had ventricular fibrillation after re-opening of the ascending aorta. Obvious hemodilution occurred after the perfusion of cardioplegia, but the hematocrit improved after CPB termination.CONCLUSION:By using cannulation of the subclavian artery rather than the aorta and with a low priming volume, we established a modified rabbit model of ASCP with cardioplegic arrest. The model has excellent repeatability and operability, which is similar to the clinic process and is suitable for the study of cerebral, cardiac and renal protection.
Perfusion 2016
OBJECTIVE:To assess the effects of tongxinluo on vascular endothelial integrity and myocardial no-reflow in early reperfusion of acute myocardial infarction.METHODS:Forty mini-swines were divided into five groups randomly, sham group, control group, low dose (0.1 g/kg), medium dose (0.2 g/kg) and high dose (0.4 g/kg) groups of Tongxinluo. It was administered at 2 hours pre-reperfusion. Animals except in sham group were subjected to 1.5 hour of coronary occlusion followed by 3 hours of reperfusion. Content of VE-cadherin, beta-catenin, matrix metalloproteinase (MMP)-2 and 9 in myocardium were evaluated; no-reflow area was examined with myocardial contrast echocardiography (MCE) at 1.5 hour of AMI and 3 hours of reperfusion.RESULTS:(1) Compared with that of normal myocardium, content of VE-cadherin and beta-catenin decreased in reperfusion and no-reflow myocardium while MMP-2 and 9 increased significantly (all P < 0.05); (2) Compared with that of control group, a high dose of Tongxinluo could increase significantly the content of VE-cadherin in both reperfusion and no-reflow myocardium, (22.2 +/- 3.2)% vs (32.0 +/- 3.9)% and (14.5 +/- 2.8)% vs (28.3 +/- 2.2)% respectively, beta-catenin, (20.5 +/- 3.5)% vs (27.3 +/- 2.9)% and (13.3 +/- 2.1)% vs (20.6 +/- 2.4)%, while reduce MMP-2, (48.3 +/- 4.1)% vs (29.4 +/- 3.5)% and (57.3 +/- 4.3)% vs (38.2 +/- 4.0)% respectively, MMP-9, (55.6 +/- 4.0)% vs (34.3 +/- 3.5)% and (62.4 +/- 4.8)% vs (44.4 +/- 4.1)%, all P < 0.05; (3) Compared with that of control group, a high dose of Tongxinluo could reduce significantly both no-reflow area, (6.6 +/- 1.7) cm2 vs (4.7 +/- 1.5) cm2, P < 0.05, and percentage (90.8 +/- 3.8)% vs (71.4 +/- 4.1)%, P < 0.05, at 3 hours of reperfusion.CONCLUSION:A high dose of tongxinluo could effectively maintain the integrity of vascular endothelium and attenuate no-reflow area in early reperfusion of acute myocardial infarction.
Zhonghua yi xue za zhi 2009
OBJECTIVE:To study the relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model.METHODS:Twenty normal minipigs were randomly divided into group A (implanted with 316L bare metal stents), group B (implanted with 605L bare metal stents), group C (implanted with PLGA coating 605L stents), and group D (implanted with rapamycin-loaded PLGA coating 605L stents). Each minipig was implanted with two same stents in left anterior descending artery and right coronary artery. Four weeks later, the animals were sacrificed and histomorphometric measurements on the stent-segment coronary arteries were made to calculate the correlation between inflammation area and neointimal area.RESULTS:Group D had the smallest neointimal area [(0.64 +/- 0.38) mm2, P < 0. 001] and inflammation area (median 0.00 mm2, P = 0.009) among all the groups, while there were no statistical differences among group A, B, and C in neointimal area [(2.09 +/- 0.90), (2.11 +/- 1.07), and (1.42 +/- 0.35) mm2 respectively] and in inflammation area (0.22 , 0.21, and 0.09 mm2, respectively). Bivariate correlation analysis showed that the inflammation area was positively correlated with the neointimal area (P < 0.001, correlation coefficient = 0.719). When stent type, mean injury score, and EEL area were adjusted, partial correlations analysis showed that the inflammation area was still positively correlated with the neointimal area (P = 0.01, correlation coefficient = 0.498).CONCLUSION:Inflammation promotes the neointimal proliferation after coronary stent implantation. Sirolimus-eluting stent may reduce the inflammatory response.
Zhongguo yi xue ke xue yuan xue bao. Acta Academiae Medicinae Sinicae 2009
OBJECTIVE:To investigate the efficacy of transplantation of mesenchymal stem cells (MSC) with gelatin microspheres containing vascular endothelial growth factor in ischemic regions in infracted swine hearts.METHODS:Twelve Chinese mini swines with infarction were randomized to receive autogenetic MSC injection to the peri-infarction area of left ventricular wall (MSC group, n = 6) or MSC transplantation with gelatin hydrogel microspheres incorporating vascular endothelial growth factor (VEGF-MSC group, n = 6). Three weeks later, left ventricular function was assessed by magnetic resonance imaging (MRI). The contrast of the MSC hypointense lesion was determined using the difference in signal intensity between the hypointense and normal myocardium divided by signal intensity of the normal region. Myocardial capillary density, the number of DAPI positive MSC and the apoptotic MSC were also determined.RESULTS:The diameter of the microspheres averaged (104.0 +/- 22.6) microm. At 24 hours after transplantation, MSC were identified by MRI as large intramyocardial signal voids at injection sites which persisted up to 3 weeks. There was no significant difference in the contrast of the lesions and in the size of the lesions at 24 hours between two groups. At 3 weeks after injection, the size of the lesions and the contrast of the lesion were decreased (P < 0.05) in both groups. The capillary density of the injection site was significantly more in the MSC-VEGF microsphere group than that in MSC group [(15.2 +/- 5.4)/HPF vs. (10.2 +/- 5.0)/HPF, t = 2.43, P < 0.05], and there were more dense DAPI labeled MSC per high power fields in injection sites of MSC-VEGF microsphere group than that in MSC group [(354 +/- 83)/HPF vs. (278 +/- 97)/HPF, t = 3.14, P < 0.05]. Moreover, the apoptosis rate of MSCs of MSCs-VEGF microsphere group was less than that of MSC group [(6.4 +/- 4.1)% vs. (11.9 +/- 4.8)%, t = 2.97, P < 0.05].CONCLUSIONS:MSC transplantation with gelatin hydrogel microspheres incorporating VEGF enhanced the efficacy of MSC in this swine model of myocardial infarction. MRI tracking of MSC is feasible and represents a preferred method for studying the engraftment of MSCs in infracted tissue.
Zhonghua xin xue guan bing za zhi 2009
OBJECTIVE:To evaluate the plaque stabilization effects of Tongxinluo and Simvastatin in aortic atherosclerosis, and to explore molecular mechanism.METHODS:Twenty-three New Zealand white rabbits underwent aortic balloon injury and fed with high-cholesterol diet for 16 weeks and then randomly divided into 3 groups: Tongxinluo group (n = 6, undergoing gastric perfusion of Tongxinluo 1 gxkg(-1)xd(-1)), simvastatin group (n = 9, undergoing gastric perfusion of simvastatin 2 mgxkg(-1)xd(-1)), and model group (n = 8, without drug administration). Another 6 rabbits were used as normal controls. Peripheral blood samples were collected 10 weeks before the administration, and 3 and 16 weeks after the administration to detect the levels of total cholesterol (TG), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), and by the end of experiment peripheral blood samples were collected to detect the levels of serum endothelin (ET) and nitric oxide (NO). Then the rabbits were killed and their aortas were taken out to undergo pathological examination. Western blotting was used to detect the protein expression of Metalloproteinase (MMP)-1 and cyclooxygenase (COX)-2 and RT-PCR was used to detect the mRNA expression of FasL and bcl-2.RESULTS:By the end of the experiment the levels of blood lipids were raised by 1 approximately 2 times in the normal group (P < 0.05), and raised more significantly in the model and intervention groups (P < 0.05 approximately 0.01), especially the TC level of the model group was raised by 40 tomes. The levels of blood lipids of the simvastatin group were significantly lower than those of the model group (P < 0.05 approximately 0.01), however, between the Tongxinluo and model groups there were no significant differences in the levels of blood lipids. In the model group the blood level of ET was raised significantly and the level of NO was significantly decreased (both P < 0.01). The ET levels of the 2 intervention groups were both significantly lower than that of the model group (both P < 0.01), and the NO levels of the 2 intervention groups were both significantly higher than those of the normal group (P < 0.01 approximately 0.05), however, there were no significant differences in the ET and NO levels between these 2 intervention groups (all P > 0.05). Sclerotic plaques were distributed intensely at high degrees in the model group. The sclerotic changes of the 2 intervention groups were significantly milder. The contents of collagen of the 2 intervention groups were 0.11 +/- 0.08 and 0.22 +/- 0.11 respectively, both significantly higher then that of the model group (0.01 +/- 0.01, both P < 0.05). The intima/media ratios of aorta of the 2 intervention groups were 0.25 +/- 0.13 and 0.28 +/- 0.12 respectively, both significantly lower than that of the model group (0.60 +/- 0.37). The macrophage amount in the plaque (RAM-11 positively stained area) of the 2 intervention groups were 0.11 +/- 0.10 and 0.06 +/- 0.43 respectively, both significantly lower than that of the model group (0.24 +/- 0.14). The levels of protein expression of MMP-1 and COX-2 in the atherosclerotic lesions of the model group were both significantly higher than those of the normal group and the MMP-1 and COX-2 protein expression levels of the 2 intervention groups were all significantly lower than those of the model group (P < 0.05 approximately 0.01), however, there were no significant differences between these 2 groups (both P > 0.05). Significant linear correlation existed in the MMP-1 and COX-2 positively stained areas (r = 0.533, P = 0.007) and protein expression level (r = 0.833, P < 0.01). Compared with the normal group, the mRNA expression level of FasL in the aorta tissue of the model group was significantly higher (2.44 +/- 0.44) and the mRNA expression level of bcl was significantly lower (0.17 +/- 0.11). Compared with the model group, the mRNA expression levels of FasL of the 2 intervention groups were 0.47 +/- 0.36 and 1.32 +/- 0.61 respectively, both significantly lower and the mRNA expression levels of bcl were 0.64 +/- 0.16 and 1.66 +/- 0.94 respectively, both significantly higher (all P < 0.05 approximately 0.01), with the FasL mRNA expression of the Tongxinluo group significantly higher than that of the simvastatin group (P < 0.05).CONCLUSION:Tongxinluo and simvastatin have the same effects of stabilizing the vulnerable plaques, and the mechanism may be related with inhibition of expression of COX-2 and MMP and reduction of the apoptosis in the atherosclerotic plaque.
Zhonghua yi xue za zhi 2006
OBJECTIVE:To assess the effect of Tongxinluo (TXL) ultramicro-pulverization in preventing and treating post-reperfusion no-reflow in mini-swine model of acute myocardial infarction.METHODS:Forty mini-swines were randomly divided into 5 groups, the control group, the three (low-, middle- and high-dose) TXL groups and the sham-operation group, with 8 in each group. After pigs in the three TXL groups were administered with TXL in a dose of 0.05g/kg, 0.2g/kg and 0.5g/kg once a day for 3 days respectively, they were made into acute myocardial ischemia/reperfusion model by ligating left anterior descending coronary artery for 3h followed with 1h of untying. Hemodynamic examination and myocardial contrast echocardiography (MCE) were conducted before and after ligation, and after reperfusion, finally, pathological analysis was done.RESULTS:Post-reperfusion ventricular function injury was significantly improved in the three TXL groups, as compared with the control group, the no-reflow area determined by hemodynamic and MCE decreased from 78.5 +/- 4.4% and 82.3 +/- 1.9% in control to 43.4 +/- 3.2% and 44.6 +/- 3.3% (low-dose), 25.2 +/- 2.4% and 25.7 +/- 4.0% (middle-dose), 24.0 +/- 1.9% and 24.9 +/- 4.2% (high-dose), respectively (P < 0.05 or P < 0.01), and the myocardial infracted area was reduced from 98.5 +/- 1.4% to 89.8 +/- 4.6%, 80.2 +/- 3.1% and 79.9 +/- 3.1%, respectively (P < 0.05, P < 0.01).CONCLUSION:TXL ultramicro-pulverization can effectively prevent and treat no-reflow after myocardial acute infarction following reperfusion, and reduce the infracted area.
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine 2006
OBJECTIVE:To evaluate the beneficial effects of adenosine on myocardial no-reflow in a mini-swine model of acute myocardial infarction (AMI) and reperfusion.METHODS:Twenty-four animals were randomly assigned to 3 groups: 8 in controls, 8 in adenosine-treated and 8 in sham-operated. The groups were subjected to 3 hours of coronary occlusion followed by 60 minutes of reperfusion except the sham-operated group. Data on hemodynamics and coronary blood flow volume (CBV) were collected. The area of no-reflow was evaluated by both myocardial contrast echocardiography (MCE) in vivo and histopathological means and necrosis area was measured with triphenyltetrazolium chloride staining.RESULTS:(1) In control group, systolic and diastolic blood pressure (SBP and DBP), left ventricular systolic pressure, maximal rate of increase and decline in left ventricular pressure (+/- dp/dtmax) and cardiac output significantly declined (P < 0.05-0.01), while left ventricular end-diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP) significantly increased at the end of 3 hours of LAD occlusion (both P < 0.01), with +/- dp/dtmax further significantly declined (both P < 0.05) at 60 minutes of reperfusion. In adenosine treated group, the changes of SBP and DBP, left ventricular systolic pressure, +/- dp/dtmax, cardiac output, LVEDP and PCWP were the same as those in the control group after AMI and reperfusion, while left ventricular systolic pressure, +/- dp/dtmax, cardiac output, LVEDP and PCWP recovered significantly at 60 minutes of reperfusion compared with those at 6 hours AMI. (2) In control group, the coronary ligation areas (LA) were similar (P > 0.05) detected by MCE in vivo and histopathological evaluation, and the areas of no-reflow were both as high as 67.5% and 69.3%, respectively. The final necrosis area reached 99% of LA. Compared with those in the control group, there was no significant difference in LA on both MCE and histopathological evaluation in the adenosine-treated group, though the areas of no-reflow on both methods were significantly decreased to 21% and 22% (both P < 0.01) and final necrosis area was also significantly decreased to 75% of LA (P < 0.05). (3) In the control group, CBV were significantly declined to 45.8% and 50.6% of the baseline at immediately after release of 3 hours occlusion and at 60 minutes of reperfusion, respectively (both P < 0.01). In the adenosine-treated group, CBV were also significantly declined at immediately after release of 3 hours occlusion, and at 60 minutes of reperfusion (both P < 0.05), though significantly increased to 79.5% and 79.9% of the baseline which were both significantly higher than those in the control group.CONCLUSION:Adenosine has an effective role in preventing myocardial no-reflow, improving left ventricular function and reducing infarct area during AMI and reperfusion in mini-swine.
Zhonghua xin xue guan bing za zhi 2005
OBJECTIVE:To evaluate the beneficial effects of diltiazem on myocardial no-reflow.METHODS:Twenty-four mini-swine were randomized into 3 equal groups: diltiazem-treated group subjected to 3 hours of coronary occlusion to cause acute myocardial infarction (AMI), followed by 60 minutes of reperfusion and injected with diltiazem into the coronary artery 1 minute before reperfusion, control group undergoing coronary occlusion followed by 60 minutes of reperfusion and injected with normal saline, and sham operation group. 5 minutes before AMI in all groups and 180 minutes after AMI and 60 minutes after re-perfusion in the diltiazem and control groups, hemodynamic data, such as heart rate (HR), left ventricular systolic pressure (LVSP). Left ventricular end diastolic pressure (LVEDP), +/- dp/dt(max), cardiac output (CO), and coronary blood volume (CBV) were measured. Myocardial contrast echography (MCE) was used to measure the left ventricle wall area (LVWA) and ligation area (LA) so as to calculate LA and to measure the area of no-reflow (ANR) so as to calculate ANR. 60 minutes after reperfusion thioflavin-S was injected into left ventricle so as to color the reperfused area and then the descending anterior branch was re-ligated and Evan's blue was injected into the left ventricle to color the area outside the ligation area. The heart was taken out to undergo histological examination.RESULTS:(1) In comparison with the values before AMI the LVSP, +/- dp/dt(max), and CO of the control group significantly declined (P < 0.05, 0.01), while the LVEDP significantly increased (P < 0.01) by the end of 3 hours after LAD occlusion; and the LVSP significantly increased and the +/- dp/dt(max) further significantly declined (both P < 0.05) 60 minutes after reperfusion. In the diltiazem group, the changes of LVSP, +/- dp/dt(max), CO, and LVEDP were the same as those in the control group after 3 hours of AMI, while the +/- dp/dt(max), CO, and LVEDP recovered significantly, more significantly than those in the control group, 60 minutes after reperfusion (all P < 0.05). (2) In the control group, the sizes of coronary ligation area (LA) measured by both MCE in vivo and histopathological evaluation were similar (P > 0.05), and the values of area of no-reflow (ANR) measured by MCE in vivo and histopathological evaluation were 78.5% and 82.3% respectively with the final necrosis area (NA) reaching 99% of the LA. There was no significant difference in LA measured by both MCE and histopathological evaluation between the control and diltiazem groups, while the values of ANR measured by both methods was significantly decreased to 19.9% and 20.6% that before AMI respectively in the diltiazem group (both P < 0.01). There was no significant difference in NA between the control and diltiazem groups (P > 0.05). The CBV of the control group was significantly declined to 45.8% and 50.6% of the baseline value respectively immediately and 60 minutes after reperfusion (both P < 0.01), while the CBV of the diltiazem group became 80.4% and 79.3% of the baseline value respectively immediately and 60 minutes after reperfusion (both P < 0.05), both significantly higher than those of the control group (both P < 0.01).CONCLUSION:Diltiazem is effective both in preventing myocardial no-reflow and improving left ventricular function, but not in reducing MI size during AMI and reperfusion.
Zhonghua yi xue za zhi 2005
OBJECTIVE:To evaluate the effects of fosinopril on myocardial no-reflow in a mini-swine model of acute myocardial infarction and reperfusion.METHODS:Twenty-four mini-swines were randomized into 3 study groups: 8 in control group, 8 in fosinopril-treated group (1 mg.kg(-1).d(-1)) and 8 in sham-operated group. Animals in the former two groups were subjected to 3 hours of coronary occlusion followed by 60 minutes of reperfusion. Data on haemodynamics and coronary blood flow volume (CBV) were collected, and the area of no-reflow was evaluated with both myocardial contrast echocardiography (MCE) in vivo and pathological means. Necrosis area was measured with triphenyltetrazolium chloride (TTC) staining.RESULTS:(1) In the control group, systolic and diastolic blood pressure (SBP and DBP), left ventricular systolic pressure (LVSP), maximal rate of increase and decrease in left ventricular pressure (+/- dp/dt(max)) and cardiac output (CO) significantly declined (P < 0.05-0.01), while left ventricular end-diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP) significantly increased at the end of 3 hours occlusion of left anterior descending artery (both P < 0.01). Compared with those at the end of 3 hours of occlusion, +/- dp/dt(max) further significantly declined (P < 0.05) at 60 minutes of reperfusion. In the fosinopril group, the changes of SBP and DBP, LVSP, +/- dp/dt(max), CO, LVEDP and PCWP were similar as those in the control group after 3 hours of acute myocardial infarction. In contrast, LVSP, +/- dp/dt(max), CO, LVEDP and PCWP recovered significantly at 60 minutes of reperfusion. (2) In the control group, the coronary ligation area was similar on both MCE in vivo and pathological evaluation, and the area of no-reflow was similarly as high as 78.5% and 82.3%, respectively, with final necrosis area reaching 99% of ligation area. In the fosinopril group, there was no significant difference in ligation area on both MCE and pathological evaluations between the fosinopril and control groups, although the area of no-reflow on both methods was significantly decreased to 24.5% and 25.2%, respectively, (P < 0.01) with final necrosis area of pathological evaluation being also significantly decreased to 88.9% of LA (P < 0.05). (3) In the control group, CBV was significantly declined to 45.8% and 50.6% from at baseline, immediately after release of occlusion (3 hours) and at 60 minutes of reperfusion (P < 0.01). In the fosinopril group, CBV was also significantly declined immediately after release of occlusion (3 hours), and at 60 minutes of reperfusion (P < 0.05), but significantly increased to 69.1% and 72.1% from at baseline, that were significantly greater than those in the control group (both P < 0.01).CONCLUSION:Fosinopril is effective in preventing myocardial no-reflow, improving left ventricular function, and reducing infarct area during acute myocardial infarction and reperfusion in mini-swine.
Zhonghua xin xue guan bing za zhi 2005
OBJECTIVE:To evaluate the effects of ischemic preconditioning (IPC) on myocardial no-reflow in a mini-swine model of acute myocardial infarction (AMI) and reperfusion.METHODS:Twenty-four mini-swines were randomized into 3 study groups: 8 in control, 8 in IPC and 8 in sham-operated. Animals in the former two groups were subjected to 3 hours of coronary occlusion followed by 1 hour of reperfusion. Data on hemodynamics and coronary blood flow volume (CBV) were collected, and the area of no-reflow (ANR) was evaluated with both myocardial contrast echocardiography (MCE) in vivo and pathological means. Necrosis area (NA) was measured with triphenyltetrazolium chloride (TTC) staining.RESULTS:In control group, left ventricular systolic pressure (LVSP), the maximum change rate of left ventricular pressure rise and fall (+/-dp/dtmax) and cardiac output (CO) significantly declined (P < 0.05, P < 0.01), while left ventricular end-diastolic pressure (LVEDP) significantly increased at the end of 3 hours of left anterior descending coronary artery occlusion (both P < 0.01), with +/-dp/dtmax further significantly declined (both P <0.05) at 1 hour of reperfusion. In IPC group, LVSP, +/-dp/dtmax, CO and LVEDP significantly recovered at 1 hour of reperfusion, compared with those in control group. In IPC group, the coronary ligation area was similar on both MCE in vivo and pathological evaluation (P > 0.05), and ANR was both also similarly as high as (16.4 +/- 2.24) % and (17.5 +/- 2.87) %, respectively, with final necrosis area (NA) reaching (78.4 +/- 3.62) %. In IPC group, ANR and final NA were significantly lower than those in control group (P < 0.05, P < 0.01). In the control group, coronary blood flow volumn immediately after release of 3 hours occlusion and at 1 hour of reperfusion were significantly lower than the baseline (both P < 0.01). In IPC group, coronary blood flow volumn were significantly higher than those in the control group (both P < 0.01).CONCLUSION:IPC is effective to prevent myocardial no-reflow, improve left ventricular function and decrease infarct area.
Zhongguo yi xue ke xue yuan xue bao. Acta Academiae Medicinae Sinicae 2005
