مقايسه بين پروتئين هاي ماتريكس خارج سلولي سياهرگ پشت پا و سرخرگ ها

چكيده انگليسي :

Comparison between Extracellular Matrix Proteins in Saphenous Vein and Arteries Shiva Safavi safavish@ag iut ac ir 11 3 2009 Departmant of Agricultural Biotechnology Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language Farsi1 Assist Prof N Nili Supervisor nilin@cc iut ac ir2 Assist Prof B E Sayed Tabatabei Supervisor sayedt@cc iut ac irAbstractAtherosclerosis is a slow and complex disease that typically starts in childhood and often progresses with age Advanced atherosclerotic plaque is characterized by a thickened intimal layer and an asymmetrical lesion thatencroaches into the lumen Plaques can grow large enough to significantly reduce the blood s flow through anartery If the blockage happens in blood vessels that feed the heart heart attack may occur Coronary arterybypass grafting CABG surgery is common in treating patients with blocked arteries CABG surgery is oneof the most frequently performed surgical procedures with greater than 500 000 coronary bypass operationsperformed each year around the world Veins and arteries are commonly used as conduits in human CABG toimprove blood flow to the heart muscle However since stenosis and occlusion rates of arterial and venousgrafts are markedly different doubts about the most appropriate conduits persist Vein grafts interposed toarteries are susceptible to the development of accelerated atherosclerosis The vessel wall is an integratedfunctional component of the circulatory system that shows different response to hemodynamic conditions andatherosclerosis plaque formation Collagen and elastin the most abundant extracellular matrix proteins of thevascular wall are responsible for the characteristic mechanical properties tensile strength and elasticity Furthermore the biomechanical properties of the vessel wall is strongly correlated with the biochemistry ofcollagen and elastin In normal vascular wall there is a balance between collagen and elastin levels Normalcollagen and elastin levels as well as their arrangement are essential for vascular wall integrity and functionwhile degradation of collagen and elastin by matrix metalloproteinases MMPs are suggested to contributeto extracellular matrix remodeling The roles of MMPs in particular MMP 2 and MMP 9 in cardiovasculardisease have been well documented We hypothesized that the differences in histology macromolecularcomposition and MMP levels of arterial and venous conduits may contribute to their differences in theirocclusion rates and graft failure To investigate this hypothesis MMP levels elastin collagen ratio andhistology of radial artery RA the left internal mammary artery LIMA and saphenous vein SV weredetermined and compared to that of aorta Specimens were obtained from 11 patients 38 66 years old whounderwent CABG All patients signed an informed consent for use of their vessel pieces that remained unusedin the procedure MMP levels were evaluated for by zymography and densitometry Collagen and elastincontent were measured by cyanogens bromide treatment and HCl digestion followed by spectrophotometricmeasurement of hydroxyproline For histological analysis the arterial and vein segments were stained withhematoxylin eosin and Verhoeff Van Gieson Pro and active MMP 2 and MMP 9 levels of LIMA wassimilar to that of aorta but were significantly higher in RA and SV Elastin Collagen ratio of LIMA 1 921 15 was similar to aorta 3 4 1 66 but it was significantly lower in RA 1 14 0 39 and SV 1 07 0 47 Histological analysis showed that atherosclerotic plaques were evident in one of the LIMA samples andalmost all RA samples The lower level of Elastin Collagen ratio and higher levels of MMP 2 and MMP 9 inRA and SV may contribute to the early pathologic remodeling of the conduits following CABG surgery These data confirm that LIMA is the best conduit for CABG surgery Key words Coronary artery bypass grafting surgery extracellular matrix matrix metalloproteinases radial artery the left internal mammary artery saphenous

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مقايسه بين پروتئين هاي ماتريكس خارج سلولي سياهرگ پشت پا و سرخرگ ها

عمل قلب باز , ماتريكس متالوپروتئينازها , شريان راديال , شريان ليما , وريد صافن