Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury.

Myocardial ischemia and reperfusion injury (MIRI), induced by coronary heart disease (CHD), causes damage to the cardiomyocytes. Furthermore, evidence suggests that thrombolytic therapy or primary percutaneous coronary intervention (PPCI) does not prevent reperfusion injury. There is still no ideal animal model for MIRI. This study aims to improve the MIRI model in rats to make surgery easier and more feasible. A unique method for establishing MIRI is developed by using a soft tube during a key step of the ischemic period. To explore this method, thirty rats were randomly divided into three groups: sham group (n = 10); experimental model group (n = 10); and existing model group (n = 10). Findings of triphenyltetrazolium chloride staining, electrocardiography, and percent survival are compared to determine the accuracies and survival rates of the operations. Based on the study results, it has been concluded that the improved surgery method is associated with a higher survival rate, elevated ST-T segment, and larger infarct size, which is expected to mimic the pathology of MIRI better.

Animal model of coronary microembolization under transthoracic echocardiographic guidance in rats.

The aim of the study was to develop a model of coronary microembolization (CME) in rats at a lower cost. We developed a novel rat model without thoracotomy and ventilation under the guidance of echocardiography. Rats were sacrificed at 3 h, 24 h and 1 month postoperatively in both the Echo-CME and Open-chest CME groups for the comparison of the modeling accuracy, mortality, cardiopulmonary circulation, pleural adhesion and ventilation-induced lung injury (VILI). Results showed that the coronary microthrombus formed at 3 h and reached its peak at 24 h postoperatively, which included platelet aggregation and fibrin web. The Echo-group increases success rates, decreased mortality, postoperative complications including pleural adhesion, cardiopulmonary dysfunction and VILI postoperatively than the Open-chest group at 1month postoperatively. The ejection fraction of the CME group decreased to 50% and obvious cardiac fibrosis formed at 3 months postoperatively. Our unique surgical method provided a platform to study molecular mechanisms and potential new pathways for CME treatment.

Effect of Kangshuanyihao Formula on the Inflammatory Reaction and SIRT1/TLR4/NF-κB Signaling Pathway in Endothelial Injury.

Endothelial injury plays an important role in atherosclerosis (AS). Kangshuanyihao formula uses therapeutic principles from Chinese medicine to supplement Qi, thereby promoting blood circulation, and remove blood stasis. The mechanism by which the formula inhibits endothelial injury was examined in a rat model of 1,25-dihydroxyvitamin D3 (VD3) intraperitoneal injection and high-fat-induced endothelial injury. Rats were randomly divided into the model, high-dose, middle-dose, low-dose, positive drug (rosuvastatin), and combination (positive drug + middle-dose) groups; 10 Sprague-Dawley rats served as the blank group. The aortic endothelium was stained with hematoxylin and eosin and the levels of blood lipids and inflammation markers (mRNA and protein) were measured. Endothelial injury, lipid levels, and inflammation were increased in the model. Kangshuanyihao formula reduced endothelial injury, improved lipid levels, and downregulated inflammation, as shown by significant reduction of the protein levels of SIRT1, TLR4, and NF-κB and mRNA levels of SIRT1, TLR4, NF-κB, IL-1ß, IL-6, and IL-12. Thus, we conclude that Kangshuanyihao formula can inhibit the inflammatory reaction in the rat model of high-fat-induced endothelial injury after intraperitoneal injection of VD3. This mechanism may be attributed to regulating the SIRT1/TLR4/NF-κB signaling pathway.