Study On High Homocysteine's Mechanism At Chronic Kidney Disease Accompanied By Cerebrovascular Disease

Background and Objective Cerebrovascular diseases(CVD)have becomethe second death reason in the world. There are about 510 ten thousand peopledying in stroke annually. Each year about 200 people suffer stroke for the firsttime among 10 ten thousand people. The incidence rate and death rate of CVD inthe people with chronic kidney disease (CKD) are far fore higher than those incommon crowd. In recent years CKD have been valued extensively, however, oneof the important factors of influencing long-term survival rate of CKD is whetherthey are accompanied by cerebrovascular and cardiovascular diseases and theirserious degree. Many Domestic and international scholars have carried on a greatdeal of research on the relationship between CKD and cardiovascular affairs, butrelating to the aspect on the CKD and CVD, there also lack systematic researchcurrently. CKD are very closed with CVD, but at present the mechanism of CKDaccompanied with CVD is still not clear completely. The prevention of CVD insufferers of CKD has many likenesses with that in common crowd, but it exists itsspecialty. The sufferers of CKD are high dangerous crowd of the CVD, whichhave more dangerous factors than common crowd, including high blood pressure,RUS activating, abnormality of blood fat, atherosclerosis (AS), diabete, anemic,homocysteine (Hcy), and abnormality of coagulation etc. Among them, thetraditional dangerous factors, such as high blood pressure, the metabolizing messof blood fat and sugar, smoking etc, which can't satisfactly explain why CKDhave such high incidence rate and death rate of CVD. Further explicating itsdangerous factors and its mechanism have more important clinical meaning to theprevention and cure of this familiar complication. Hcy is a kind of amino acidscontaining sulphur, and body inside can't synthesize, only can be produced frommetabolism of sulphur ammonia sour in food. In recent years a great deal ofresearch expressed: Blood Hcy level 's Going up, has important function in themechanism of AS, embolism and infarction diseases, such as stroke, coronaryatherosclerotic heart disease and vein infarction disease, which is one of theindependent dangerous factors. Because of the incidence rate and death rate ofCVD going up obviously in CKD, the relationship between high Hcy blooddisease and CVD have caused people's concerns. This research systematiclyobserved blood tatal homocysteine (tHcy) level of CKD sufferers and its affectingfactors, intially researched Hcy's possible mechanism causing AS, then explicitedHcy's function on CKD accompanied by CVD, further providing experimentaland theorial base for clinic studying on mechanism and prevention of CKDaccompanied by CVD.Method1. research objects: 97 CKD sufferers(cerebral infarction:29, cerebralhemorrhage:3).45 patients with CVD which liver's and kidney's function arenormal(cerebral infarction:29, cerebral hemorrhage:16).Healthy control group: 35.2. Observing index and examining method: Efficiently liquid colorfluorescence method measured blood tHcy level;Measured kidney function,blood fat, blood plasma white protein, blood sugar, RBC and Hb with thefull-automatic bio-chemical analytical instrument and blood cells analysisinstrument;Examined common carotid artery intima-medial thickness (IMT) andcarotid artery intima spot as indexes of AS using high distinguish color doplar.3. Experiments outside body adopting vascular smooth muscle cell (VSMC)from person's navel artery developed by sticking pieces method as experimentmaterial;Measuring Hcy's inducing VSMC apoptosis percentage with Flowcytometry;Examining expression amount of protein related apoptosis Bcl-2, Baxand Caspase-3 with RT-PCR.Result a: The relationgship beteeen Hcy and its affecting factors of CKD andCVD1. The tHcy in CKD is obviously higher than that in healthy control groupand simple CVD group, and Group hemodialysis (HD) is obviously higher thangroup non-HD in CKD.2. In CKD, The tHcy in CKD is obviously higher than that in healthy controlgroup, Where RBC and Hb of CVD group are significantly lower than those ofnon-CVD group.3. In accepting HD sufferers of CKD, the tHcy at 4 hours after HD isobviously lower than that before HD, Where tHcy at 20h after HD is significantlymore rising than at 4 hours after HD, but still lower than that before HD.4. In CKD group tHcy level presented just related with serum CRE level andages.5. The Logistic multivariate gradual return analysis showed that the factorsof tHcy, TG, RBC and Hb are intimated with CKD accompanied by CVD, wheretime of HD, sex, age, average artery pressure etc. showed no obvious influence onCVD.Result b: The relationship between Hcy level and AS in CKD.1. The average IMT of CKD sufferers is all higher than that of the healthycontrol group at the same age segment. Checking totally 15 examples with spot,among them the spot checked rate of CKD group is all higher than that of healthycontrol group at 40~64 years segment. The average IMT and spot checked rate offemale in CKD are obviously higher than those in healthy control. In male theaverage IMT obviously higher than that of the healthy control, but spot checkedrate had no obvious difference. The average IMT value, IMT thickness percentageand spot checked rate in HD group are all obviously higher than those in non-HDgroup.2. In CKD, carotid artery IMT value and Hcy level in spot group areobviously higher than those in non-spot group.3. According to Logistic multivariate gradual return analysis between carotidartery IMT value and related factors showed: The influencing factors of arotidartery IMT value contained tHcy level, age, time of HD. The tHcy level affectedthe degree to the biggest, exceeded age and time of HD.4. In 97 CKD sufferers, the incidence rate of CVD in spot group significantlyhigher than that in non-spot group.Result c: Hcy's influence on apoptosis and expression of protein relatedapoptosis Bcl-2, Bax and Caspase-3 in person's VSMC that developed outsidebody.1. With sticking pieces method, observing the VSMC developed outsidebody with upside-down microscope, the cells presented long shuttle forms, stringforms and triangle forms. They had already stuck the wall at 6h after spreadinggeneration. They Growed fine cell layers after 4-5 days, presenting many layersand pole alignments. After α -actin immunohistochemistry, it is clear that the cellsare widespreadly positive observed from low-time microscope, and α-actin is evento distribute in the plasma observed from high-time microscope. It expressed thatthese cells are typical VSMC.2. Hcy to the person's influence on VSMC apoptosisFlow cytometry result shows: At 100μmol/L of Hcy developing liquids forhatch to 24hs, cell apoptosis had not gone up obviously. But with the increasing ofthe density, the cell apoptosis went up obviously. At 1000μmol/L it hit the biggestvalue, and then desended. It showed that the Hcy presented amount dependence toinduce person's VSMC apoptosis inside the scope of the density of1000μmol/L.At 550μmol/L of Hcy developing liquids for hatch to 6hs, apoptosisdid not show to go up, and then went up gradually, it hit the biggest value at 24hswhich expressed that Hcy presented time dependence to induce person's VSMCapoptosis inside 24hs.3. Hcy's influence on expression of protein related apoptosis Bcl-2, Bax andCaspase-3 mRNA in person's VSMC. The result of RT-PCR showed: Person'sVSMC at different density of Hcy developing liquids for hatch to 24hs, theexpression quantity of Bax mRNA rose with the increasing of density in thecertain scope of density, where the expression quantity of Bcl-2 mRNA had norelation with density. At the same time Hcy in certain scope of density can ascendthe ratio value of Bax/Bcl-2, and presented density dependence. The expression ofCaspase-3mRNA amount hit the biggest value at 1000 μmol/L of Hcy whichexpressed that Hcy presented amount dependence to go up at this scope.Conclusion1. The tHcy level of CKD are widespread to go up, and presents just relatedwith the serum CRE level and age. The tHcy level in HD group is obviouslyhigher than that in non-HD group.2. HD can clearance some circulating tHcy, but can't make it maintain in thelower level with long hours.3. CVD have relation with tHcy, TG, RBC and Hb in CKD, but havn'trelation with time of HD, sex, age, average artery pressure.4. The carotid artery structure change in CKD group is more serious than thatin healthy control group which their age matches mutually, and has relation withthe tHcy level. High tHcy blood disease is one of the independent dangerousfactors of AS of CKD sufferers.5. Hcy can induce person's VSMC apoptosis, which may increase Bax genelevel, lightly descend Bcl-2 gene levels, and then cause to ratio abnormalitybetween Bax and Bcl-2, further activate Caspase-3 to carry out. Inducing person'sVSMC apoptosis is one of the mechanism that the Hcy causes AS.