动物实验,心肌缺血,速效救心丸 z-bo 2020-09-03 735

　　Background: Coronary heart disease and ischemic cardiomyopathy are the most important types of cardiovascular diseases. Modern medicine has made significant progress in the treatment of cardiovascular diseases. Primary treatments such as antiangina drugs and anticonvulsants are the first choice for cardiovascular disease. SX is one of the most effective Chinese patent medicines for the treatment of cardiovascular and cerebrovascular diseases. It has been used to treat coronary heart disease, angina pectoris, and myocardial infarction. SX has been shown to quickly relieve angina pectoris and improve symptoms in small doses. In addition, there are no obvious symptoms, side effects and drug resistance. Recent studies have shown that SX can significantly improve myocardial ischemia, improve microcirculation, reduce the incidence of myocardial infarction, reduce blood viscosity, increase coronary blood flow, expand coronary blood vessels, and improve myocardial blood supply. In this study, we used ligation of the left anterior descending branch (LAD) to prepare a model of myocardial ischemia to explore the anti-myocardial ischemia effect of SX on the heart. During the experiment, measure the area of myocardial infarction, blood gas changes, hemodynamics and epicardial electrocardiogram, serum creatine kinase isoenzyme MB level (CK-MB), lactate dehydrogenase (LDH), malondialdehyde (MDA) ), superoxide dismutase (SOD) and other parameters.

　　Animals: All dogs are raised under laboratory conditions, maintained at a moderate temperature and humidity, and can eat and drink freely. After one week of domestication, 44 healthy dogs were screened according to body weight and electrocardiogram, and randomly divided into six groups: model group (normal saline, 1ml/kg), high-dose group (SX 25.60mg/ml/kg), medium-dose group (SX, 12.80 mg/ml/kg), low dose group (6.40 mg/ml/kg), isosorbide dinitrate (ISD 0.80 mg/ml/kg) and sham operation group (normal saline, 1ml/kg), number of animals in each group They are 7, 7, 9, 6, 7, and 8. Animals that died in the experiment are not included.

　　Surgical preparation: This study uses an acute myocardial ischemia (AMI) experimental model. The dog was fasted overnight before the operation and allowed to drink freely. Perform the open chest anesthesia canine model described previously. Dogs are anesthetized by intravenous injection of 30 mg/kg sodium pentobarbital, and additional doses can be supplemented if necessary. Using aseptic operation technology, the constant temperature operation table keeps the dog body at a constant temperature. The dog’s trachea is intubated and ventilated with an air respirator. A polyethylene catheter was inserted through the right external jugular vein for venous blood gas analysis and blood sample examination. The left femoral artery was connected with a polyethylene catheter for arterial blood gas analysis and blood pressure measurement. Perform an 8-10 cm thoracotomy in the fifth left intercostal space, with the heart suspended in the pericardial cradle. A 3-5 mm left circumflex coronary artery (LCX) is separated from the origin, and an ultrasonic flow probe is placed around the LCX vessel to measure coronary blood flow (CBF). Separate the first and second diagonal branches of the left anterior descending coronary artery (LAD) section, and use the same method to measure. A double-stranded 7.0 silk thread passing through the LAD closes the two ends, and the double-filament ligation is cut to become a ligature. The first ligature is tightened to reduce the LAD flow by 50% for 10 minutes, and then the second ligature is tightened with a needle to reduce blood flow by 90%. Sham dogs undergo the same operation without ligating the LAD. The infusion tube is inserted into the duodenum and treated with medication. Thirty minutes after ligation, all dogs were injected with drugs or saline through the infusion tube.

　　Experimental procedure: Hemodynamic measurement: The coronary angiography catheter is inserted into the left ventricle through the right femoral artery, and then connected to the MP150 analog-to-digital converter. Measure heart rate (HR), mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), the maximum and minimum values of the first derivative of LVSP. In addition, a polyethylene catheter was inserted into the left femoral artery to measure systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP). And measure CBF. Myocardial blood flow (MBF, ml/min per 100 grams), the formula is: MBF=CBF×300/heart weight. The respective MBF is divided by the mean arterial pressure (MAP) to calculate the coronary vascular resistance (CVR). Hemodynamic data were collected before operation, before operation, and 180 minutes after operation.

　　Measurement of epicardial electrocardiogram: The epicardial electrocardiogram has 30 unipolar silver wire electrodes connected to MP150 and placed on the front surface of the left ventricle. The characteristic electrical parameters such as ST-segment elevation of ECG were recorded from 5××6 matrix points on the anterior surface of the epicardium. All data are analyzed with EEG PowerLab system software. The epicardial electrocardiogram was measured 30, 60, 90, 120, and 180 minutes after pre-occlusion, pre-administration and medication. ST-segment elevation exceeding 2 mV is considered as the ischemic standard for calculating the degree of myocardial ischemia and the extent of myocardial ischemia.

　　Serum enzyme activity and blood gas analysis: Collect blood samples from venous sinuses. Use a diagnostic kit to measure the levels of creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH), malondialdehyde (MDA) and SOD. Collect venous sinus blood and arterial blood into an anaerobic heparinized syringe, and immediately perform oxygen tension (oxygen partial pressure) and blood oxygen saturation (SO2) analysis through the blood gas analyzer. All blood samples were measured at 30, 60, 90, 120, and 180 minutes after pre-occlusion, before administration and after administration.

　　Measure the infarct size: After 180 minutes of closure, the heart is extracted and the atrium is removed. Quickly wash the ventricle with physiological saline, place it at -20°C for 30 minutes, cut into 5 equal parts, and then put in 1% triphenyltetrazolium chloride (TTC) phosphate buffer solution for 10 minutes. After TTC staining, viable myocardium was stained red, and necrotic myocardium was still pale. Measure the ischemic area and the non-ischemic area, and calculate the weight of each ischemic area using the weight of the ischemic area/total left ventricular weight×100%.

　　Result: The effect of SX on the infarct size: Analyzing the ischemic myocardial infarction area can visually observe the effect of SX against ischemia. Figure 1 shows the percentage of cardiac infarct area at 180 minutes of ischemia. After ischemia, the myocardium has an infarct area of about 17.84±2.83%, which continuously decreases to 7.33±4.39% (SX low dose group), 6.03±3.13% (SX middle dose group), and 5.55±1.72% by increasing the concentration of SX (SX high-dose group). The same effect as the SX high-dose group was also observed in the ISD group. The infarcted area is white, and the non-infarcted area is red. After SX treatment, the whole white and red signs are significantly improved. There are significant differences between the model group and the SX administration group.

　　The effect of SX on the degree and scope of myocardial ischemia: Check the epicardial electrocardiogram to compare the degree and scope of myocardial ischemia during the experiment. In the model group, Σ-ST increased from 18.85±11.09 mV to 228.78±122.39 MV, and N-ST increased significantly from 0.33±0.52 points to 24.67±7.47 points. After SX and ISD treatment, the above indicators were significantly reduced at 180 min compared with the model group. In addition, ΣST and N-ST were significantly reduced by 69.18% and 26.75% after treatment in the SX high-dose group. After closure, the epicardial electrocardiogram changed significantly, and the st segment increased significantly. However, the high dose (25.6 mg/kg) of SX caused a marked depression of the ST segment of the epicardial ECG.

　　SX's influence on hemodynamics: Hemodynamic monitoring is one of the important methods to measure and explain the performance of the cardiovascular system. Therefore, the effect of SX on hemodynamics was studied. The results showed that there was no significant difference between the six groups in pre-occlusion. Compared with the model group, the high-dose SX and ISD administration group caused a significant decrease in MAP and LVEDP. LVSP decreased significantly after 180 min in the SX high, medium, and low dose groups and ISD group. In the model group, CBF and MBF decreased, and CVR increased significantly, but this trend was significantly reversed in the SX administration group and the ISD administration group.

　　The effect of SX on serum CK-MB, LDH, MDA content and SOD activity: The changes in serum myocardial enzyme levels were confirmed during acute myocardial ischemia. In the current study, the effects of SX on CK-MB, LDH, MDA and SOD are examined. Compared with the model group, after 90-180 minutes of occlusion, all SX administration groups and ISD administration groups significantly reduced serum CK-MB, LDH, and MDA levels, and increased SOD levels. These results indicate that SX can inhibit lipid peroxidation and increase the production of superoxide dismutase to protect against myocardial ischemic injury.

　　Measure the effect of SX on blood gas: blood gas analysis can reflect oxygen metabolism and oxygen consumption during acute myocardial ischemia. The blood gas data of the six groups are shown in Table 4. Compared with the model group, CaO2 increased slightly in the SX and ISD treatment groups, but the difference was not statistically significant.

　　Conclusion: The current research shows that SX exerts a significant anti-ischemic angina pectoris effect. SX is an effective Chinese medicine for the treatment of ischemic heart disease. SX's mechanism of action can improve hemodynamics, expand coronary arteries, and reduce myocardial oxygen demand and workload.