Effect Of Suramin On The Rabbit Autologous Vein Graft Intimal Proliferation

Effect of suramin on the rabbit autologous vein graft intimal proliferationPrefaceCoronary heart disease is one of the serious diseases, which threaten human health. Coronary artery bypass graft surgery (CABG) is an important means of treating the disease, especially for those multi-vessel disease and patients with multiple risk factors. Vein graft vessels because of their easily obtained,in sufficient numbers, fit easily and will continue to be widely used, but its high rate of restenosis is still no good solution.Surgical mechanical injury, ischemia-reperfusion injury, as well as hemodynamic changes, which can cause vein graft endothelial cell detachment and dysfunction; stimulus such as platelet-derived growth factor (PDGF) and other growth factors release; lead to vascular smooth muscle cells (SMC) from the contractile to the proliferative changes. SMC proliferation and migration to the intima, synthesis, secretion of extracellular matrix, promote intimal hyperplasia. SMC proliferation and migration is a key step in intimal hyperplasia.Suramin is a growth factor inhibitor. It is used to treat AIDS and some malignant tumors patients in 70s, have powerful pharmacological effects:The mechanism is to block growth factor and its receptor binding,and have a certain role in inhibiting protease class. In rabbit angioplasty model of systemic suramin,it can inhibit the arterial intimal proliferation. This article was to explore the effect of the local short-term application of suramin on vein graft intimal hyperplasia.Materials and methodsMaterials:1. Animals:Healthy Japanese white rabbits, male, weighing 2.5-3.0kg 2. Major reagentPCNA antibody, PDGF-B antibody, suramin, DAB test kit, instant SABC immunohistochemistry test kit, ethanol, pentobarbital, paraformaldehyde, Xylene, hydrogen peroxide,2.5% glutaraldehyde,1% osmium tetroxide, etc.3. Major equipments:Surgical instruments,8-0 surgical suture with needle, micro-based equipment Electronic balance, analytical balance, incubators, refrigerators, LEITZ 1512 slicer, OLYMPUS optical microscope, Image analysis system,JEM-1200EX transmission electron microscope, cameras, etc.Methods:Establish rabbit model of carotid artery bypass graft, Sumianxin intramuscular injection, intraperitoneal injection of sodium pentobarbital anesthesia, cervical midline incision, the right external jugular vein is anastomosed to the right common carotid artery. Experimental group were given to deal with suramin 1mg/ml, the control group received saline treatment, and sham group with no graft. After 21 days, use 4% paraformaldehyde solution or 2.5% glutaraldehyde fixation, line measurement of intima-media thickness, intima-media ratio by HE stain; Check PCNA, PDGF-B positive cell counts use immunohistochemical analysis; Observe the ultrastructural changes of vascular smooth muscle by transmission electron microscopy.Statistical analysisAll datas were demonstrated by mean±standard deviation(χ±S). Use the SPSS 13.0 software for statistical analysis. Comparisons each two groups when statistically significant and use T test, p<0.05 when difference significant.Results1. H-E staining:The thickness of vein neointimal in case group is less than that of control group. In control group, intimal thickness and medial thickness (44.4±10.80μm,68.3±10.09μm) is significantly lower than saline group (67.2±11.31μm,84.1±10.30μm). The difference is statistically significant (P<0.01). 2. Immunohistochemical staining:Proliferating cell nuclear antigen (PCNA), expressed in the nucleus, brownish yellow, brown. PCNA-positive cells decreased significantly in suramin group; Platelet-derived growth factor (PDGF-B), expressed in cytoplasm showed brown-yellow,brown. PDGF-B positive cells were significantly reduced in suramin group.3. TEM observation:In control group, vascular smooth muscle cells significantly increased cell body, nucleus chromatin aggregation, nuclear shape irregular, cytoplasm contains rough endoplasmic reticulum, ribosomes and mitochondria and large vesicles and other organelles showed proliferative changes. In suramin group, smooth muscle cell structure remains intact over, spindle-shaped nucleus, smooth membrane, evenly distributed chromatin nuclei, less cytoplasmic organelles, showing the characteristics of contraction-type.DiscussionLocal short-term application of suramin on the rabbit autologous vein graft intimal hyperplasia inhibition may be related to inhibition of platelet-derived growth factor (PDGF-B) expression, inhibition of vascular smooth muscle cell proliferation.