Establishment Of Myocardial Ischemic Model Induced By Self-thrombus And Effects Of Shuangshen Ningxin Capsule On The Model

Cardiovascular disease is one of the highest death rate diseases of human, and ischemic cardiomyopathy acts the main affect. At present, myocardial ischemic models have mamy defects, such as big damages to model animals, blood vessel could not be recanalized, great difference of clinical pathogenesy of myocardial ischemia. It is necessary to unify and definite the choice of experiment animal, experiment technique of establishment model, standard of myocardial ischemic model. The experiment study of Chinese medicinal materials anti-myocardial ischemia has many progresses. The study has used the active component of Chinese medicinal materials on the foundation of Chinese medicinal materials complex prescription. But there are also many defects of the myocardial ischemia, because of the simple model and the single detection indexes, and the model could not fit the effective feature of Chinese medicinal materials. So it can not precisely observe long-term pharmacodynamic action and feature of the effects Chinese medicinal materials on myocardial function. It is necessary to launch the technology study of myocardial ischemic model.At first, this experiment launched a new method to establish myocardial ischemic model in miniature swines. We approached the methods of LAD balloon injury, LAD injection thrombin, LAD balloon injury adding injection thrombin, LAD insertion contractile ring, feeding rich fat feeds adding LAD balloon injury and LAD injection self-thrombus. At last we choosed the methods of LAD injection self-thrombus to develop the study by comparing these methods. On the base of the model, this study observed the effects and action features of Shuangshen Ningxin capsule on a series of indexes to synthetically appraise myocardial ischemic model, which including coronary angiography, 30 points body surface electrocardiogram, noninvasive hemodynamics, biochemistry, common ultrasonometry, myocardial tissue dopplerechocardiography, quantitative histology and pathohistology in animal model.1 Exploration of the methods to establish myocardial ischemic model by using intervention technique1.1 LAD balloon injury to establish myocardial ischemic model1.1.1 Methods Miniature swines were anaesthetized with pentobarbital. Through the cervical incision, a 6F sheath was inserted into the right common carotid artery. A Launcher 6F guiding catheter was positioned in the left coronary arterial ostium, left coronary angiography was performed with C-arm. After left coronary angiogram, a balloon catheter (2.5mm or 3.0mm ) , directed by the balloon wire, was introduced into the middle segment of the LAD. The LAD was dilated three times by the balloon at the 10 atm press.1.1.2 Results Three days later after the LAD balloon injury in miniature swines, coronaryarteriongraphy showed the LAD was not stenosis, and the cardiac muscle did not show myocardial ischemia.1.2 LAD injection thrombin to establish myocardial ischemic model1.2.1 Methods Miniature swines were anaesthetized with pentobarbital. Through the cervical incision, a 6F sheath was inserted into the right common carotid artery. A Launcher 6F guiding catheter was positioned in the left coronary arterial ostium, left coronary angiography was performed with C-arm. After left coronary angiogram, a 2.5mm balloon catheter (balloon was cut to inject thrombin) , directed by the balloon wire, was introduced into the middle segment of the LAD. 0.5ml 50U thrombin was injected into the LAD.1.2.2 Results Seven days later after the LAD injection thrombin in miniature swines, coronary arteriongraphy showed the LAD was not stenosis, and the cardiac muscle did not show myocardial ischemia.13 LAD balloon injury adding injection thrombin to establish myocardial ischemic model1.3.1 Methods Miniature swines were anaesthetized with pentobarbital. Through the cervical incision, a 6F sheath was inserted into the right common carotid artery. A Launcher 6F guiding catheter was positioned in the left coronary arterial ostium, left coronary angiography was performed with C-arm. After left coronary angiogram, a 2.5mm or 3.0mm balloon catheter, directed by the balloon wire, was introduced into the middle segment of the LAD. 0.5ml 50U thrombin was injected into the LAD after the LAD balloon injury in the miniature swine.1.3.2 Results Seven days later after the LAD balloon injury adding LAD injection thrombin in miniature swines, coronary arteriongraphy showed the LAD was stenosis, and the cardiac muscle showed infarction focus, the cardiac muscle appeared larger area of degeneration, necrosis, fibroplasias, inflammatory cell infiltrat and granulation tissue hyperblastosis.1.4 LAD insertion contractile ring to establish myocardial ischemic model1.4.1 Methods Miniature swines were anaesthetized with pentobarbital. Through the cervical incision, a 6F sheath was inserted into the right common carotid artery. A Launcher 6F guiding catheter was positioned in the left coronary arterial ostium, left coronary angiography was performed with C-arm. After left coronary angiogram, a contractile ring, directed by the balloon wire, was introduced into the middle segment of the IAD of the miniature swine.1.4.2 Results Seven days later after the IAD insertion contractile ring in miniature swines, coronary arteriongraphy showed the LAD was stenosis, the contractile ring placed into the middle of the IAD after the heart excised, and the cardiac muscle showed infarction focus, the cardiac muscle appeared larger area of degeneration, necrosis, fibroplasias, inflammatory cell infiltrat and granulation tissue hyperblastosis.1.5 Feeding rich fat feeds adding LAD balloon injury to establish myocardial ischemic model1.5.1 Methods Miniature swines were anaesthetized with pentobarbital after feeding two weeks rich fat feeds. Through the cervical incision, a 6F sheath was inserted into the rightcommon carotid artery. A Launcher 6F guiding catheter was positioned in the left coronary arterial ostium, left coronary angiography was performed with C-arm. After left coronary angiogram, a balloon catheter, directed by the balloon wire, was introduced into the middle segment of the LAD to dilate the LAD. Rich fat feed was gieven to the miniature swines for two months after operation.1.5.2 Results Two months later after operation in miniature swines, coronary arteriongraphy showed the inside of LAD was thin, the inner wall of LAD was rough, the serum TRIG, CHO, HDL-C, LDL-C obviously increased, with the histopathologic examination, the endangium of LAD showed hyperplasy, thicken, affluent foam cells and scleratheroma changes, the cardiac muscle appeared larger area of degeneration, necrosis, fibroplasias.1.6 LAD injection self-thrombus to establish myocardial ischemic model1.6.1 Methods Miniature swines were anaesthetized with pentobarbital after feeding two weeks rich fat feeds. Through the cervical incision, a 6F sheath was inserted into the right common carotid artery. A Launcher 6F guiding catheter was positioned in the left coronary arterial ostium, left coronary angiography was performed with C-arm. After left coronary angiogram, a Envoy 5F guiding catheter, directed by the balloon wire, was introduced into the middle segment of the LAD. 0.5ml self-thrombus was injected into the LAD.1.6.2 Results Six days later after operation in miniature swines, coronary arteriongraphy showed the LAD was almost obstructed, the cardiac muscle showed infarction focus, the cardiac muscle appeared larger area of degeneration, necrosis, fibroplasias, inflammatory cell infiltrat and granulation tissue hyperblastosis.2 Study of Shuangshen Ningxin capsule on myocardial ischemic model induced by self-thrombus injection in miniature swines2.1 Methods and Results2.1.1 Model preparation and groups After the LAD injection self-thrombus, 24 qualified miniature swine were randomly divided into four groups, 6 pigs in each group: model group, fed with normal pig diet;diltiazem group, fed with pig diet mixed with diltiazem 5mg/kg per day;Shuangshen Ningxin capsule group, fed with pig diet mixed with Shuangshen Ningxin capsule 16mg/kg and 8mg/kg per day. During the experiment, special technician was appointed to observe the pigs eating so as to ensure the absorbed drugs dose. After 6 successive days of medication, the animals committed sacrifice.2.1.2 Results(1) Coronary angiography The LAD was embolized after auto-embolus injection, six days later after medication , the LAD embolism of model group was also serious, but that of Shuangshen Ningxin capsule group was obviously lessen after six days later(2) Body surface electrocardiogram Six days after medication, the E -ST increased obviously in model group. The E -ST of pigs treated with Shuangshen Ningxin capsule was reduced. The difference was significant compared with that of model. After giving normal diet, there was no significant change of the scope of myocardial ischemia (N-ST) in the models. While Shuangshen Ningxin capsule -treated animals showed significant effect ofreducing the N-ST.(3) Haemodynamics Before the operation, the haemodynamic indexes of the two groups were basically similar. When ischemia lasted for six days, the CO, CI, LCW and LCWI of model group showed to decrease dramatically. On the other hand, the SVRI of model group raised obviously, compared with those of model group before operation. The CO, CI, LCW and LCWI of Shuangshen Ningxin capsule group were significantly higher than those of model group, SVR and SVRI of Shuangshen Ningxin capsule group decreased obviously compared with those of model group.(4) M-type of two dimensional echocardiography and tissue doppler imaging Six days after medication, in model group, the ventricular wall changed thin, chambers he art dilated, wall motion weakened. Shuangshen Ningxin capsule cut down the LVIDd, LVIDs, ESV and EDV, increased the EF, lowered the IVRT, augmented ventricular wall motion velocity and tissure tracement in the apex cordis segment of left ventricle anterior wall.(5) Biochemistry After medication six days later, the SOD activity of Shuangshen Ningxin capsule group was significantly increased than that of model group, MDA content of Shuangshen Ningxin capsule was decreased obviously compared with that of model group.(6) Quantitative histology and pathohistology The ischemic area of model group and Shuangshen Ningxin capsule group were indicated by NT-B staining. The ischemic area, percentage of heart and ventricle of Shuangshen Ningxin capsule group were significantly lower than those of model group. The myocardial ischemic pathohistology changes were appeared in miniature swine of model group. The cardiac muscle of model group appeared larger area of degeneration, necrosis, fibroplasias, inflammatory cell infiltrat and granulation tissue hyperblastosis. The cardiac muscle of Shuangshen Ningxin capsule group also appeared pathological lesion, but the area and degree of lesion lessened after six days medication.3 ConclusionThis experiment established a new method to establish myocardial ischemic model in miniature swine after several methods comparing, which induced by using C-arm and intervention technique to inject self-thrombus into the middle segment of LAD without thoracotomy. We had set up a series of indexes to synthetically appraise myocardial ischemic model, including coronary angiography, 30 points body surface electrocardiogram, noninvasive hemodynamics, biochemistry, common ultrasonometry, myocardial tissue dopplerechocardiography, quantitative histology and pathohistology.This myocardial ischemia model is close to the clinical pathology and physiology process of coronary heart disease, because the self-thrombus has better autoploidy with experimental animals, mini-pigs do not generate rejection, thrombus embolism coronary artery is unobstructed by the drug action. Applying the myocardial ischemia model not only can observe the pharmacodynamic action and mechanism of myocardial ischemic antagonist, but also can observe the pharmacodynamic action and effect feature of thrombolytic drug.Thismodel avoids complicated tnoracotomy, so there is little damages and no effects on pathology and physiology function to animals. Cardiovascular disease can be chronically, continually, systematicly observated is owing to long-term administration. This model has the features of repeatability, avoiding complicated side effect and easily manipulate. There are extensive application perspective on the study of coronary heart disease myocardial ischemia and new drug exploitation.Shuangshen Ningxin capsule had the actions of anti-myocardial ischemia on improvement the construction and function of cardiac muscle cell in myocardial ischemic miniature swine. The action channels may be anti-lipid peroxidation, improvement the pathohistological changesand the diastolic function, increase wall motion, inhibition the cardiac muscle degeneration, necrosis, fibroplasias, inflammatory cell infiltrat, granulation tissue hyperblastosis and anti-thrombus action.