Objective

2

To compare the feasibility of establishing the rat model of acute coronary syndrome with combined blood stasis and poison by lipopolysacharide （LPS） injection， ligation of coronary artery and different combinations of the two methods.

Method

2

A total of 225 male SD rats were randomly divided into sham operation group， simple coronary artery ligation group， first injected LPS group ［LPS（5 mg·kg）injection 24 h before coronary artery ligation］ and follow injected LPS group ［LPS（5 mg·kg）injection 10 min after coronary artery ligation］. The indexes of each group were detected at 3， 24， 72 h after modeling， and the model was comprehensively evaluated. The general state and macroscopic evaluation indexes of traditional Chinese medicine （TCM） syndrome （tongue and pulse） of rats in each group were observed. ECG and echocardiography were used to evaluate cardiac function， and the myocardial ischemia and infarction areas were measured by Evans blue/2，3，5-triphenyltetrazolium chloride （TTC） staining. The content of creatine kinase isoenzyme （CK-MB）， lactate dehydrogenase （LDH）， creatine kinase （CK）， and troponin T （cTnT） in serum as well as interleukin-1

β

（IL-1

β

） and IL-6 changes were determined by biochemical method or enzyme-linked immunosorbent assay （ELISA）. Hematology analyzer was adopted to determine the white blood cell （WBC） count， and the four coagulation indexes， platelet aggregation rate， hemorheology and other coagulation evaluation indexes were also detected. The myocardial tissue was observed by hematoxylin-eosin（HE）staining.

Result

2

After 3 h of modeling， compared with the conditions in sham operation group， the R， G and B values of tongue of rats （

P

<

0.01）， pulse amplitude （

P

<

0.01）， and cardiac function in simple coronary artery ligation group were decreased， and the color of hypoglossal veins became purple（

P

<

0.01）. The content of CK， LDH， cTnT， IL-1

β

and IL-6 in serum（

P

<

0.05）， myocardial infarction area（

P

<

0.01）， and total number of WBCs （

P

<

0.05）were increased. Compared with simple coronary artery ligation group， first injected LPS group and follow injected LPS group had increased hypoglossal veins， decreased R value of tongue and elevated cTnT content （

P

<

0.01）， while follow injected LPS group had reduced B value of tongue， decreased cardiac output （CO）（

P

<

0.05）， increased IL-1

β

content， and thinned left ventricular anterior walls at end-systole （LVAWs）（

P

<

0.01）. After 24 h of modeling， compared with sham operation group， simple coronary artery ligation group presented significantly decreased R， G and B values of tongue， lengthened purplish dark hypoglossal veins （

P

<

0.01）， reduced pulse amplitude（

P

<

0.01） and cardiac function， enlarged myocardial infarction area（

P

<

0.01）， increased whole blood viscosity， platelet aggregation rate， fibrinogen （FIB）， shortened prothrombin time （PT） and thrombin time （TT）（

P

<

0.01）， and elevated total number of WBCs （

P

<

0.01）and content of CK， LDH， cTnT and IL-6 in serum（

P

<

0.05）. Compared with the conditions in simple coronary artery ligation group， the pulse amplitude， R， G and B values of tongue （

P

<

0.01）， and ejection fraction （EF） and fractional shortening （FS） scores （

P

<

0.05）dropped， and hypoglossal veins were deepened and lengthened（

P

<

0.05）， and cTnT content was increased（

P

<

0.01）in first injected LPS group and follow injected LPS group. However， follow injected LPS group had thinned LVPWs， increased LDH content， platelet aggregation rate（

P

<

0.05）， myocardial infarction area， and total number of WBC， level of IL-1

β

（

P

<

0.05）， and shortened TT（

P

<

0.01）. Additionally， 72 h after modeling， compared with sham operation group， simple coronary artery ligation group showed significantly reduced pulse amplitude， lowered R， G and B values of tongue， thickened and lengthened hypoglossal veins（

P

<

0.01）， decreased cardiac function， and increased content of cTnT， FIB， whole blood viscosity（

P

<

0.01），platelet aggregation rate， level of IL-6 and IL-1

β

（

P

<

0.05）. Compared with the conditions in simple coronary artery ligation group， the hypoglossal veins of the first injected LPS group and the follow injected LPS group were more purple， and the content of cTnT was boosted（

P

<

0.01）， whereas follow injected LPS group had decreased pulse amplitude， R， G and B values of tongue， EF and FS scores （

P

<

0.05）， and enlarged myocardial infarction area（

P

<

0.01）.

Conclusion

2

Compared with the other modeling methods and models at different modeling time， the established model by LPS injection 10 min after coronary artery ligation for 24 h was more consistent with the clinical characteristics of acute coronary syndrome with combined blood stasis and poison.