Preventive Effect Of Intravenous Injection Of Polymer Dextran Induced As Early Lesions And Ginkgo Biloba

1. Experiment backgroundCardiovascular and cerebrovascular disease, a very common disease in modern society, of which incidence, mortality, and disability are quite high, known as the number one killer of developed countries, has become one of the serious diseases of human life and health in our country.It is not as high as Western countries, but the trend is upward.Cardiovascular and cerebrovascular disease, common pathology-Atherosclerosis (Atherosclerosis, As) has been a breakthrough of mechanism and prevention. For one hundred years, many scholars committed to study the mechanism of As, and put forward many hypotheses that include the main theory of thrombosis, inflammation hypothesis, lipid infiltration theory, monoclonal theory, damaging response theory, and oxidative stress theory. These hypotheses reflect the multiple factors that form the complex mechanisms of As from different sides. But under the guidance of these existing theories, even though a lot of people's lifestyle changes, but the current drug is limited, which can only explain the part of patient's pain and not treated fundamentally.60 to 80 years of the 20th century, several scholars had proposed the hypothesis that microcirculation disturbance of vasa vasorum of the large artery induced the formation of As. Preliminary evidence suggests that microcirculation disturbance of vasa vasorum played an important role in the formation of As. But it had not been reasearhed on the prevention and treatment of drugs.2 Experiment objectives①By the tail vein injection of polymer dextran, the model of early atherosclerosis lesions was established in rats②Reproposing the hypothesis that microcirculation disturbance of vasa vasorum of the large artery induce the formation of As.And emphasising on prevention to generate new methods and drugs. of prevention③Researching the prevention of Ginkgo Leaf Tablets on early atherosclerotic lesion.3 Experiment methodsThe 40 male rats (Wistar)were randomly divided into five groups,8 rats in every group. Every group was feeded the normal dietThe normal group was feeded the normal diet; The saline group was injected the saline(2ml/kg)by tail vein;The polymer dextran group was injected the 10% polymer dextran(2ml/kg) by tail vein;Ginkgo Leaf Tablets group was injected the 10% polymer dextran(2ml/kg) by tail vein, and received Ginkgo Leaf Tablets by gavage (6.5mg/kg/d); Calcium Dobesilate capsules group was injected the 10% polymer dextran (2ml/kg) by tail vein, and received Calcium Dobesilate capsules by gavage (0.14g/kg/d).Regular feeding for 3 months, the first 91 days,rats were killed and got vascular. All of rats were anesthetized with 3.5% chloral hydrate(0.33ml/1kg) by intraperitoneal. We got blood from abdominal aorta, then cut the right atrial appendage, inserted in the left ventricular apex.First,we washed systemic vascular with 0.9% saline(180 mL); Then, we conducted in vivo and in fixed with 10% formaldehyde solution (180mL). About 30 minutes later, dissected the abdominal cavity in rats, removed thoracic aorta, aortic organs then which were separated into 10% formalin fixative and fixed. Finally,we did some studies in morphology by HE and MASSON,EVG,immunohistochemistry staining.4 Experiment Results4.1 blood test results4.1.1 Complete blood count test resultsAnalysis of variance:comparing with the normal group, the model group, RBC, MCHC, and PLT increased with significantly statistical difference (p<0.01). Comparing with model group, Ginkgo Leaf Tablets and Calcium Dobesilate capsules group PDW decreased, with significantly statistical difference (P<0.01); Ginkgo Leaf Tablets and Calcium Dobesilate capsules group differences were not statistical difference. Saline group and normal group, the difference was not statistical difference.The results showed that intravenous injection of high molecular dextran caused a hypercoagulable state in the body, while the value of traditional Ginkgo Leaf Tablets and Calcium Dobesilate capsules can reduce the PDW, PDW play a reduced role; Also it ruled out the effects of inflammatory to As.4.1.2 Blood biochemistrytest resultsStatistical analysis:comparing with the normal group,model group, TG decreased with significantly statistical difference. The remaining indicators did not change significantly, not statistical difference.These results suggest that intravenous injection in rats caused by dextran polymer TG reduction, which lead to long-term application of high molecular dextran on liver function damage. To sum up the results, thus we can exclude the effects of high blood sugar and high cholesterol to As.4.1.3 Hemorheology test resultsAnalysis of variance:Comparing with the normal group, model group, Whole blood viscosity and plasma viscosity test indicators were increased with significantly statistical difference(p<0.01). Saline group increased slightly, with not statistical difference; Comparing with model group, Calcium Dobesilate capsules group and Ginkgo Leaf Tablets group, whole blood viscosity and plasma viscosity, which reduced are both statistically significant (p<0.05). Calcium Dobesilate capsules group compared with Ginkgo Leaf Tablets, whole blood viscosity (ls)and plasma viscosity, had statistically significant difference (p<0.05).These results suggest that dextran polymer injection caused changes in blood rheology. plasma viscosity of Ginkgo Leaf Tablets and Calcium Dobesilate group reduced. Calcium Dobesilate capsules are better to lower blood viscosity (ls) and plasma viscosity slightly in terms of the role of traditional Ginkgo Leaf Tablets. This may be due to microcirculatory disturbance induced by dextran polymer.4.2 Pathology resultsHE staining,the model group:endomembrane is not smooth and full, seen the visible uplift and thickening.Endothelial cells increased significantly, and subendothelial cells were seen aggregation of large quantities. Internal and external elastic laminae multiple fracture, were not continuous,even showed cells walking through in breaks; Medial smooth muscle layer, cells were different of sizes, the nucleus size was not very unified, and orientation was disorder; MASSON, EVG stain:collagen fibers in the film increased significantly, loose layers of elastic fiber structure, disorder, multiple separation,fracture, or even disappear, external elastic plate multiple fracture.Saline group a slight pathological changes. Medicines pathological changes compared with the model group had a certain degree of ease, with the Ginkgo Leaf Tablets group, the pathological changes slightly worse.From the HE staining, we found that a large number of cells were aggregat. As for what these cells was, to verify whether it was macrophages, we did immunohistochemical staining. CD68 is a macrophage surface antigen, which showed positive cytoplasmic dyed brown. Studies showed that intimal macrophages under a lot of positive expression, no expression of the control group. Research showed that intravenous injection of dextran polymer, resulted in a large number of macrophages in subendothelial accumulation, which suggested the formation of early changes of As.5. Experiment conclusions Blood test statistics showed that after intravenous injection of polymer dextran, the blood flow changes of indicators in rats occurred that may result in the microcirculation; Blood test results showed that the arteries were not caused by inflammatory changes, so we can rule out the impact of inflammation inducing the As; Blood biochemical detection index changes indicate that did not cause high blood sugar, high blood lipid formation, excluding their impact on the model of As.Pathological findings:normal group had no pathological changes; The saline group had a slight pathological changes, which may be connected with stimulating and stress-related; Model group,Ginkgo Leaf Tablets group,and Calcium Dobesilate capsules are formed of early lesions of As, suggesting that the model of As was successfully established; Ginkgo Leaf Tablets and Calcium Dobesilate capsules on prevention played a certain role, and the role of Ginkgo Leaf Tablets group is slightly better than Calcium Dobesilate capsules.