| Objective and BackgroundThe Percutaneous coronary intervention (PCI) has become a standard treatment for stenosis of the coronary artery disease. Drug-eluting stent (DES) (including paclitaxel and rapamycin), has widely used in interventional treatment of coronary heart disease for its significant role in the anti-restenosis. Even for acute myocardial infarction, DES is still safe , and can reduce the incidence of in-stent restenosis and revascularization. However, there are still 10% -20% DES restenosis rate in placed DES, some of DES did not reduce and even some major adverse cardiovascular events (MACE) incidence, late stent thrombosis is the focus of great concern. Currently considered to cause in-stent restenosis is the main pathology of vascular smooth muscle (VSMC) and endothelial cells (VEC) proliferation and migration. Paclitaxel is a microtubule inhibitor, mainly inhibit cell cycle G0/G1 phase and G2/M phase, inhibition of spindle formation and cell division with the transmembrane signal transduction and gene expression, thereby inhibiting microtubule all dependent Cellular processes, including proliferation, migration and secretion, nano-molar concentrations of paclitaxel that can effecti- vely inhibit vascular smooth muscle cell proliferation and migration. Paclitaxel- eluting stent implantation in vivo blood vessel after a significant inhibition of VSMC proliferation and migra- tion, significantly inhibits neointima formation, but also inhibits the migration and proliferation of VEC and therefore delay the repair of a complete membrane, which is a late stent thrombosis pathology. Although the incidence of stent thrombosis is lower, but it has serious consequences, a higher mortality rate, is a catastrophic complication of DES, is one of the main causes of death for PCI. So how to minimize the risk of thrombosis is the focus of anti- proliferative drugs research frontier at home and abroad.PCI perioperative thrombosis mechanism includes two components: thrombin activation, and platelet activation, coagulation of which play in the process a connecting role. Thrombin addition to fibrinogen into fibrin in blood clotting process, but also through activation of thrombin receptor directly or indirectly caused by thrombin-mediated molecular and cellular interactions. With coagulation cascade reaction process, thrombin not only increase the endothe- lial permeability, but also trigger a series of vascular injury response; has hormone-like role in promoting proliferation after vascular injury; with platelets, protein kinase and adhes- ion, form a complex network connections, thus thrombin not only plays an important action in the beginning of atherosclerosis and restenosis, but also throughout the entire process. Different from heparin, hirudin is a direct thrombin inhibitor, its role of inhibition and inactivation on thrombin is not dependent on antithrombinâ…¢, heparin cofactorâ…¡, protein C or tissue factor pathway inhibitor, and not by platelet Combination of inactivation, inhibit thrombin- induced platelet aggregation, so it has good anticoagulant and antithrombotic effect.The subject is to discuss the effect of paclitaxel and hirudin complexes on the growth of vascular endothelial cells and smooth muscle cells by cell culture, to find the appropriate ratio of paclitaxel and hirudin to maximize the inhibition of smooth muscle cells, and minimum the inhibition of endothelial cell, to provide a theoretical basis of the research and development of the stent paclitaxel and hirudin complex. The topic of taxol by cell culture and then hirudin complex on vascular endothelial cells and smooth muscle cell growth. Subjects were divided into two parts:Partâ… : Effects of Hirudin on the Growth of Rabbit Endothelial Cells and Vascular Smooth Musele Cells (SMC)MethodsThe 3-5 generations of rabbit endothelial cells(EC) and vascular smooth musele cells (SMC) were respectively incubated in a 96-well culture plate, then co-incubated with different doses of hirudin(0.78ug/ml,1.56 ug/ml,3.13 ug/ml,6.25 ug/ml,12.50 ug/ml,25.00 ug/ml) ,every doses were added into 6 holes,the first 6 holes added RPMI-1640 for control group.After co-incubated 48 hours detected the 7groups of cells growth activity by MTT colorimetric method,then the absorption(A) was determined.Results1. Compared to the effect of RPMI-1640 on endothelium(EC), low dose and medium and high dose of hirudin were not apparently inhibit the growth of endothelium cells(p>0.05);2. For the vascular smooth musele cells (SMC), low dose of hirudin have no apparently effects on the growth of vascular smooth musele cell(sp<0.05), medium dose and high dose of hirudin inhibited the growth of vascular smooth musele cells,made the cells density low, the absorption(A)was determined lower than the RPMI-1640 group(p<0.05).ConclusionLow to high dose of hirudin have no apparently effects on the growth of the rabbit endothelium cells;otherwise,low dose of hirudin have no apparently effects on the growth of the rabbit vascular smooth musele cells,but medium and high dose of hirudin inhibited the growth of vascular smooth musele cells apparently. Partâ…¡: Effects of Paclitaxel and Hirudin on the Growth of Rabbit Endothelial Cells and Vascular Smooth Musele Cells (SMC)MethodsThe 3-5 generations of rabbit endothelial cells(EC) and vascular smooth musele cells (SMC) were respectively incubated in a 96-well culture plate, then co-incubated with different doses of paclitaxel and hirudin, every doses were added into 6 holes,the first 6 holes added RPMI-1640 for control group.After co-incubated 48 hours detected the 5 groups of cells growth activity by MTT colorimetric method,then the absorption(A)was determined.Results:1. Compared to the effect of single paclitaxel on endothelium(EC),the effect of paclitaxel and low dose of hirudin were apparently on the growth of endothelium cells(p<0.05),and decrease the inhibition ratio of the growth of endothelium cells by single paclitaxel;2. For the vascular smooth musele cells (SMC),paclitaxel and low,medium and high dose of hirudin have apparently effects on the growth of vascular smooth musele cells(p<0.05),all can increase the inhibition ratio of the growth of SMC by single paclitaxel.ConclusionPaclitaxel add low dose of hirudin have no apparently inhibition effects on the growth of the rabbit endothelium cells, but inhibited the growth of vascular smooth musele cells apparently.
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