Experimental Study On Mechanism Of Homocysteinemia Resulting In Atherosclerosis And The Intervention Of Medicine To The Pathogenisis

Homocysteinemia (Hhcy) is defined as the pathological statement of high concentration in plasma. Hhcy is known as the independent risk factor of atherosclerosis (AS). As is reported, Hhcy exists in approximately 40% patients suffering from early cerebrovascular and cardiovascular diseases, peripheral vascular diseases or paroxymal thrombotic diseases. According to the latest research on the mechanism of Hhcy associated to AS, it seems to be excessive oxidative stress, the biological activity of NO decreasing, injury of endotheliocyte, inflammatory reaction, immoderate proliferation of vascular smooth muscle and so on. However, the exact pathogenisis is still unknown. The research on Hhcy and the intervention of medicine to Hhcy resulting in angiopasy is almost focused on the function of folic acid (FA) and vitamin B (VB), but no final conclusion is arrived. In the recent, there is no any study on the traditionally antiatherosclerotic medicine, such as angiotensin-converting enzyme inhibitor (ACEI), lipid regulators, antiplatelet drug as a kind of cheap one in our country. In our research, rabbit are modeled as AS with food rich in cystein(Cys). The pathogenesis of AS correlated with Hhcy is disscussed from the following aspects that Oxidative stress, inflammatory reaction, immonohistochemistry and the pathomorphological changes of arterial affection in light microscope and electron microscope. Seven experimental groups are established with FA, VB12, captopril, simvastatin, chondroitic acid (CS) fenofibrate, clopidogrel and sowthistle-leaf ixeris seedling. At the novel point of view, the mechanism of Hhcy resulting in AS and the efficient prevention and cure is revealed firstly in the domestic and overseas. Our research is expected to provide the novel data in the field.Methods:①AS model sharing Hhcy is established by the method of raising rabbit with the food rich in cysteine.②Control group (CG) is raised normally. Experimental rabbit are divided into eight groups randomly: Hhcy control group administrated with no any drug; seven experimental groups administrated with FA, VB12, captopril, simvastatin, CS, fenofibrate, clopidogrel and sowthistle-leaf ixeris seedling for 8 weeks respectively.③Serum homocysteinc is quantitated by euzyme linked immunosorbent assay (ELISA).④Serum malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) is measured by colorimetric method to evaluate the peroxidatic reaction.⑤Serum NO, nitricoxide synthase (NOS) related is quantitated by colorimetric method to evaluate the function of endothelia. The expression of Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) positive cells in the artery wall of rabbit is detected by immunohistochemical LSAB method.⑥Serum interleukin-8(IL-8) , monocyte chemokine protein-1 (MCP-1), IL-6, hypersensitivity C-reactive protein (hsCRP) is analyzed by the double antibodies sandwich ELISA method to evaluate immunoinflammatory reaction. The expression of MCP-1 positive cells is detected by immunohistochemical LSAB method.⑦The pathomorphological changes of rabbit's artery wall is observed in gross, light and electron microscope microscrope.Results1. AS rabbit model is established with Hhcy successfully.2. 8W later, level of serum Hcy in FA group and B12 group is decreased significantly, compared with Hhcy control group, while that of captopril, simvastatin, CS, fenofibrate, clopidogrel and sowthistle-leaf ixeris seedling guop is similar to Hhcy control group.3. Oxidation in rabit model can be caused by Hhcy, which is featured in weaker activity of serum SOD and GSH-Px decreasing and higher level of MDA. FA, VB12, sowthistle-leaf ixeris seedling and simvastatin arise the activity of serum SOD and GSH-Px. CS, captopril, fenofibrate, clopidogrel is resistant to the peroxidation just by increasing activity of SOD.4. Hhcy may cause endothelial injury by decreasing NO level, NOS activity and inducing expression of ICAM-1 and VCAM-1.In the study, FA, VB12, sowthistle-leaf ixeris seedling, simvastatin, captopril, CS, clopidogrel, is proved to resist to the decreasing of NO level, NOS activity and decrease the expression of ICAM-1 and VCAM-1. Fenofibrate has no significant influence on NO level and NOS activity but on decreasing the expression of ICAM-1 and VCAM-1 to protect the vessels.5. Hhcy can cause inflammatory reaction by increasing serum IL-8, IL-6, MCP-1, CRP level and the expression of MCP-1 in artery wall. FA, VB12, sowthistle-leaf ixeris seedling, simvastatin and CS can decrease those inflammatory factors level and the expression of MCP-1 in artery wall. Fenofibrate has no influence on serum MCP-1 and IL-8 but similar to clopidogrel in other aspects. The later can't change serum MCP-1 level but has similar efficiency with FA, VB12, sowthistle-leaf ixeris seedling, simvastatin and CS in other aspects.6. Pathomorphological changes: Oberserved in naked eye, the aortic endomembrane of rabbit in CG is smooth and white. The plaque of deep color emerged in aortic endomembrane of rabbit in Hhcy control group. The change is slighter in the other drug groups. The changes is more clear when observed in light microscrope. The aortic wall structure of GC is normal, featured in smooth endomembrane and smooth muscle laying regularly. Comparatively, the aortic wall structure of Hhcy control group is in disorder. The aortic wall is concavoconvex diffusely. Many foam cells, a few fibrocyte and some collagen aggregated in endomanbrane and smooth muscle proliferated in middle layer with inflammatory cells infiltrating. The sharp comparison proves the successful establishment of experimental model. Meantime, the pathological changes of artery in FA, VB12, captopril, simvastatin, CS, fenofibrate, clopidogrel and sowthistle-leaf ixeris seedling group is slighter than that of Hhcy control group. Vascular smooth muscle can be induced to proliferate obviously by Hhcy, but the characteristic is weakend by FA, VB12, captopril, simvastatin, CS, sowthistle-leaf ixeris seedling effectively. Fenofibrate seems to have weaker protection to artery than the other drugs.conclusion. From the aspects, such as Pathomorphology, immunohistochemical assay, oxidative stress, inflammatory reaction, endothelial function and so on, the mechanism of Hhcy resulting in AS is discussed in our study firstly in domestic and overseas. Ingesting excessive dose of Cys will cause Hhcy to result in sever AS. The concrete mechanism is seemed to oxidative stress, endothelial injury, inflammatory reaction, smooth muscle proliferation in artery wall. FA, VB12, sowthistle-leaf ixeris seedling can reduce serum Hcy level. FA, vb12, sowthistle-leaf ixeris seedling, CS, captopril, simvastatin, fenofibrate, clopidogrel can resist in the induction of Hhcy to AS from some degree. Our research is expected to be valuable for the deeper discussion on the relationship between Hhcy and AS.