| PrefaceAbdominal aortic aneurysm (AAA) is characterized by its progress enlargement , curve and rupture . In China , the incident rate of AAA among the old, aged over 65 ,is 2% -9%. Although operation, intravascular shunt can prevent it from rupturing and save patients life. There are still disputes on its trigger factors. It is well known that the degradation and reconstruction of extracellular matrix plays an important role in the development of AAA. Prior studies has put attention on the enzymes such as MMPs which degrade the structure protein of ECM. Recently, with the research of tumor metastasis, heparin sulfate proteoglycan (HSPG) , another important part of ECM, its function in triggering the development of AAA has been got importance, while, there is a few report on this subject in China.ObjectiveApplying mice model of abdominal aortic aneurysm to analysis the expression of heparin sulfate proteoglycan (HSPG) mRNA in abdominal aortic aneurysm tissue and discuss its affect on the development of AA by the changing of its content, and its mechanism.Method20 wistar mice, weighed 250g -400g,were divided into two groups. 10 into experiment group ,10 into control group. The surgery was performed with microscopic assistance, the infrarenal aorta was cannulated with a thin polyethylene catheter via the lift common iliac artery, A laparotomy was performed , and thevena cava was carefully dissected from the aortic to isolated all lumber branches, Perfuse pancreatic elastase in to the aortic witch has been dissected with pressure. Measure the diameter of the aortic before ,right after, and 14days after the operation. The diagnosis standard of AAA is the enlargement rate is over 100%. After 14days, the samples of two groups were analysis with HE stain, VVG stain. In situ hybridization was applied to detect mRNA expression of Heparin sulfate proteoglycan( HSPG). Statistical analysis adopted x test for the qualitative data result1. Morphology: After 14days, the diameter of perfused part of abdominal a-orta increased distinctly, with thicken of vascular wall. There are 8 cases reached the diagnosis standard, then they were performed histological examination and HSPG in situ hybridization. 2 Histology: histology evaluation of specimens revealed fragmentation and depletion of elastin in the media of AAA. and intimal thickening, with inflammation cell soakage 3. In situ hybridization; the positive signal is located in the plasma and expresses yellow. The control group revealed high positive expression , while the experimental group showed negative or low positive expression. (P <0.01).DiscussionHeparin sulfate proteoglycan ( HSPG) is a kind of proteoglycan carbohydrate. Which is the main element of base membrane. Heparanase (HPa) is the only enzyme that can degrade it in human body , its activity is in line relation with HSPG degradation products.Our study indicated that heparin sulfate proteoglycan ( HSPG) influence the onset and development of AAA through the following mechanisms, 1, The expression of HSPGmRNA in the experimental group is severely decreased compared with that of normal abdominal tissue indicating that HSPG degradated by HPa, on one hand, destroys the stabilization of unstructured protein and the integrity of base membrane. Therefore lower the vascular wall stress. 2, As it has been showed above , in the experimental group, the expression of HSPG in the media of AAA decreased evidently concomitant with much fragmentation and de-pletion of elastin and glue which indicates that the HSPG& degradation by HPa , activated fibrinolysin and pro - MMPs, which are the main enzyme to destroy e-lastin and other structure protein. 3, the study detected that there are inflammation cells soakage in the media of AAA wall where there are hardly any HSPGm-RNA expressed, which indicates that inflammation cells release HPa destroying the unstructured protein. The degradation of HSPG make varies kinds of cyto-kines and chemotaxis factors which were linked to HSPG through HS, release into the...
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