| Atherosclerosis was etiologic basis of ACL Oxidized low - density lipoprotein (ox - LDL) is believed to play an important role in the de-velopment of atherosclerosis. Oxidative modification of low - density lipoprotein ( LDL) developed rapid accumulation of LDL in macro-phage and the formation of foam cell . Because of high antioxidant lev-el in plasma, LDL oxidation is suggested to occur mainly in the suben-dothelial space of the atherial wall. Copper - mediated oxidation of LDL in vitro may micmic oxidation of LDL in vivo. It has only smaller reported the association of oxidation of LDL and TAS with incidence of atherosclerosis cerbral infaction ( ACI) . The purpose of this experi-ment was to investigate the association of susceptibility of LDL to oxi-dation and plasma TAS with incidence of ACLExperimental data and method1. subjectsAccording to the diagnostic criteria from the 4 Chinese cerebral-vescular disease assocition,64 ACI hospitalized patients confirmed by brain CT and/or MRI were chosen, including 45 male s and 19 fe-males , mean age 59.39 + 12.08 years old. All patient were examinedin order to exclude some diseases which could affected the plasma lip-id metabolism .Another 42 healthy person who didnt suffered any disease were chosen to the control group, including 27males and 15 females, mean age 51.-66 +9.43 years old.2. Experimental method(1) Blood sampling8ml Blood sample were obtained by venipucture from the clients in the morning before treatment, after 12h of fasting. 5ml were drawn into tube containing EDTA ?Naj( Ig/L) , which were instantly put in-to icewater, After centrifugation (9min 2000 x g) at 4??)C. Plasma sample were collected into polypropylene vial, then stored at - 80Ti until use,3ml into normal tube for collected serum, serum was prepared by centrifugation at 2000 x g for l0min and -SOT! until the a-nalysis(2) Preparation of low density lipoproteinLDL was isolated by density ?gradient ultracentrifugation meth-od. Plasma (0. 9ml) was adjusted to a density of 1. 400Kg/L by adding 0.3556g of KBr, then put 1. l00Kg/LKBr 1.8 ml on top of the plasma, and the solution was then overlaid with isotonic saline (9.3ml d = 1.006Kg/L). The balanced and sealed tubes were centrifugated at AVC278940 g (65000rpm) for 5. 5h at 15t in a HITACHI SCP85H ultracentrifugation. After untracentrifugation, the LDL -con-taining band located in the center of the tube , was collected by aspi-ration , marked and preserved. The LDL - containing fraction was dia-lyzed in the dark for 24h at 4℃ against 3L of 0. Olmol/L phosphate buffer ( PH =7.4) containing 0.16 mol of NaCl,10 umol of EDTA.(3)LDL oxidation-LDL (0. 05g/L LDL protein) was incubated with a freshly pre-pared CuCl2.2H20 solution (final concentration 10 umoI/L) for 3h at 37?C in a UV - Visible spectrophotomer ( model UV -160 with GPS -controller, shimadzu, Japan ). Absorbance at 234nm was recorded automatically at 2min interval. Using this method, LDL oxidation can be divided into 3 phage: a lag phage, a propagation phage and a de-composition phase.(4) TAS of plasma cbntentIn this assay, ABTS?with a peroxidase (methglobin) and H202 to produce a radical cation ABTS? It has stable blue - green color, which is measured at 600nm. Antioxidant in the added sample cause suppression of this color production to a degree which is proportional to their concentration. Plasma TAS was measured by end pointed method with HITACHI 7170 auto analyzer.(5) Serum nitric oxide {NO determination Serum NO was determined by enzymatic methods.(6) Other measurementTC , TG , HDL - C , LDL - C , apoA I and apoB were quantified by the commercially available kits using automated tech-nique.(7) statistical analysisAll data were expressed as mean +SD, statistical comparison of the data was carried out using the Student' s t - test and p <0.05 was considered to be significant.Result1. The comparison of susceptibility to oxidation of LDL in ACI group with that in controls.There was sign...
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