Study For Rabbits Atherosclerosis Caused By Hyperhomocysteinemia Combined With Balloon Injury Using To Animal Model

Object The research combines hyperhomocysteinemia triggered by highmethionine diet with atherosclerosis caused by balloon injury of the abdominalaorta, providing experimental model for further drug intervention experiments.Methods1. Animal for experiment:32healthy male New Zealand whiterabbits, weighing2.0to2.5kg purchased from the Lanzhou UniversityExperimental Animal Center.2. Modeling:2%L-methionine was used to feed New Zealand white rabbits.After two weeks, balloon injury was introduced to cause intimal injury of theabdominal aorta. After12weeks a high homocysteine hyperlipidemia andatherosclerosis model was created.3. Animal grouping:32New Zealand rabbits were randomly divided into fourgroups: normal control group; balloon injury group; methionine fed group andmodel group (2%L-methionine diet+abdominal aorta balloon injury).4.Outcome measures:①The four groups took blood tests respectively at thestage of0week,2weeks and12weeks for blood homocysteine concentration;②The four groups all took blood tests at the end of12weeks to determine theconcentration of blood lipids (TG, Tc, and LDL-c, HDL-C by Ox-LDL);③Thefour groups took blood tests at the end of12weeks to determine the concentrationof MMP-9and NF-κ B;④The results of specimens oil red O staining ofabdominal aortic from the four groups were observed at the end of12weeks;⑤ The results of abdominal aorta hematoxylin-eosin staining from the four groupswere observed of at the end of12weeks.Results Two weeks after being given2%L-methionine particle feed, therabbit serum homocysteine level was significantly higher (P <0.05), and thenabdominal aortic balloon injury was introduced. Vascular segments ofdamageunique atherosclerotic lesions were observed after12weeks, and at thesame time the rabbits had larger plaque area and more severe intimal injury asopposed to the case of simply giving abdominal aorta balloon injury and2%L-methionine pellets.1. Blood homocysteine concentrations of the four groups at0week, the2ndweek and the12th week:0week, the serum Hcy of32samples was within normaldistribution, with the normal range of4.03~15.11μmol/L, Hcy differencesbetween the groups was insignificant (P>0.05);2weeks, the Hcy levels ofmethionine group and model group were significantly higher than the normalgroup and injury group (P <0.05);12weeks, Hcy of each group were quite at thelevel of two weeks (P>0.05).2. Relevant factors for serum atherosclerosis of the four groups wererespectively measured at the end of the12th week to compare with the controlgroup, showing that: rabbit serum Ox-LDL values of the methionine group andmodel group were significantly increased (P <0.05) with significant differences (P<0.05), while that of the injury group is not significantly increased (P>0.05).Rabbit serum MMP-9, VCAM-1of all groups had no significantly increased (P>0.05), compared with control group.3. Semi-quantitative detection of MMP-9and NF-κ B level in abdominalaorta of all groups: compared with the control group, MMP-9in rabbit abdominalaortic tissue of injury group, methionine group and model group was significantly increased (P <0.05), The comparison between these groups was significantlydifferent (P <0.05). Level of rabbit abdominal aorta NF-κ B of injury group,methionine group, model group was significantly increased (P <0.05). Results ofthree groups were significantly different (P <0.05).4. Abdominal aorta atherosclerotic plaque formation of the groups (oil red Ostaining): Rabbits from the normal group were observed to have smooth surface ofabdominal aortic intima, without oil red O coloration. Rabbits from the straingroup were observed to have visible endothelial denudation and intimalhyperplasia, especially at the blood vessels branch openings, with no oil red Ocoloration on the surface. As for rabbits from the methionine group, a small areaof red fatty plaques was observed on the of surface abdominal aortic, accountedfor about4.6%of the total plaque area. Rabbits from the model group had unevensurface of abdominal aortic intimal, showing bright red lipid streaks and plaques,with an area of about9.6%. Methionine group and model group were significantlydifferent on the plaque area (P <0.05).5. Pathological changes of abdominal aorta among the groups (HE staining×100): Rabbits from the control group were observed to have smooth abdominalaorta endothelial, with vascular smooth muscle cells arranged in neat rows.Rabbits from the strain group were observed abdominal aortic intimal thickening,middle VSMC-1derangement, and the percentage of intimal/medial thickness ofabout29.7%. Rabbits from the methionine group were observed intimal thickening,intima/media thickness in percentage of32.5%. Rabbits from the model group,intimal thickening, intima/media thickness in percentage of43.1%. Methioninegroup and model group showed significant difference in percentage of intima/media thickness (P <0.05).Conclusion1. To feed New Zealand white rabbits with high methionine particles feedings for two weeks leads to formation of high hyperhomocysteinemia,with similar concentration level as that of12weeks.2. Balloon injury of the abdominal aorta can trigger and lead to the formationof atherosclerosis, but only fibrous plaques, commonly known as a hard plaque;while the joint high hyperhomocysteinemia can lead to fatty plaque, which isusually said the soft plaque.3. Homocysteine hypertriglyceridemia is one of the independent risk factorsfor rabbit atherosclerosis.4. The combined effect of two factors can cause atherosclerosis soft plaque.However, the modeling cycle is relatively short. If allowed3-6months, theexperiment would be able to form a more typical model for a large area of softplaque.5. The model can be adopted in terms of traditional and transgenic drugintervention for soft plaque due to hyperhomocysteinemia.6. Oxidative stress caused by rabbit high homocysteine blood and theabdominal aorta balloon injury is an important mechanism for formation ofatherosclerosis;7. Vascular remodeling caused by rabbit high homocysteine blood and theabdominal aorta balloon injury is an important mechanism for formation ofatherosclerosis;8. Endothelial injury caused by rabbit high homocysteine blood and theabdominal aorta balloon injury is an important mechanism for formation ofatherosclerosis;9. Inflammation caused by rabbit high homocysteine blood and the abdominalaorta balloon injury is an important mechanism for formation of atherosclerosis.